The central question in UFO research is deceptively simple Do UFOs exist? Once reports are systematically investigated, however, a substantial proportion can be attributed to identified or otherwise explainable phenomena (IFOs). This raises a further and more complex question: What is the statistical relationship between identified and unexplained reports, and what can this relationship tell us about the phenomenon under investigation?
The subject is inherently complex, involving differences in reporting practices, investigative methodologies, classification criteria, geographical coverage, and the quality and completeness of available data. The purpose of the present exercise is therefore modest. Rather than attempting to draw definitive conclusions, it seeks to assemble and consolidate, in tabular form, data extracted from both historical and contemporary databases, thereby providing a basis for comparison and further discussion.
This preliminary analysis originated from an examination of the relationship between reports classified under psychological or mental causes and those attributed to hoaxes or deliberate fraud within major UFO report databases. The systematic collection and analysis of UFO reports—whether through field investigation or subsequent analytical study—is a demanding undertaking, and relatively few UFO organizations have approached the task in a comprehensive and methodologically consistent manner.
The United States Air Force’s Project Blue Book (1952–1969) represents one of the most substantial attempts to investigate UFO reports systematically. Nevertheless, its published statistics comprise several distinct sets of figures, reflecting differences in the sources and methods of reporting available during that period. Several researchers have reevaluated the same data using different criteria, including (or not) insufficient-data cases in their formulae to calculate the percentage of IFOs.
Major organizations such as the Center for UFO Studies (CUFOS), for example, devoted considerable resources to research and publication but did not establish a comprehensive case database, with the notable exception of the one-year study conducted by Allan Hendry. Routine case investigation was consequently left, to a significant extent, to other national UFO organizations, such as the Aerial Phenomena Research Organization (APRO), which itself did not publish a comprehensive catalogue of the reports it collected.
The National Investigations Committee on Aerial Phenomena (NICAP, 1956–1980), another major UFO organization in the United States, likewise did not produce a formal sightings catalogue in the conventional sense. Following the organization’s dissolution, the late ufologist Francis Ridge compiled a chronology of cases on the NICAP website. I have subjected this chronology to numerical analysis, with the assistance of artificial intelligence, in order to derive what may be regarded as reasonable estimates for the relevant categories. These estimates have subsequently been incorporated into the table below.
A similar methodological problem arises when attempting to assess the data contained in the National UFO Reporting Center (NUFORC), one of the world’s largest repositories of UFO reports. In the absence of direct access to first-hand investigative information, I again employed artificial intelligence as an analytical aid to examine the database’s 160,314 cases, representing its reported total as of May 16, 2026. The resulting figures should therefore be regarded as indicative rather than definitive.
The table that follows is intended primarily as a starting point for further investigation. It should not be interpreted as presenting definitive statistical conclusions, but rather as an attempt to bring together disparate historical and contemporary datasets in a form that facilitates comparison. Its principal objective is to stimulate additional analysis, encourage methodological discussion, and contribute to the gradual refinement of this initial compilation of data (with the usual operational limitations).
| Database | Country | Sightings | UFO | IFO◊ | PsychΣ | Hoax | P+H Total | Case collection | Source |
| Blue Book (a) | Worldwide | 12,618 | 5.6% | 94.4% | ʘ | ʘ | ʘ | 1952-1969 | [1] |
| Blue Book (b) | Worldwide | 13,134 | 4.5% | 95.5% | 0.5% | 0.9% | 1.4% | 1952-1969 | [2] |
| Blue Book (c) | Worldwide | 13,032 | 4.6% | 95.4% | 2.0% | 0.9% | 2.9% | 1952-1969 | [3] |
| Blue Book (d) | Worldwide | 13,134 | 4.9% | 95.1% | 0.5% | 0.9% | 1.4% | 1952-1969 | [4] |
| Blue Book (e) | Worldwide | 13,449 | 3.1% | 96.9% | 2.3% | 0.8% | 3.1% | 1952-1969 | [5] |
| Blue Book (f) | Worldwide | 12,580 | 3.0%⁋ | 97.0%⁋ | 4.2%⁋ | 1952-1969 | [6] | ||
| Blue Book (g) | Worldwide | ~15,000 | 80%Ͷ | 20%Ͷ | 2.5%Ͷ | 5.0%Ͷ | 7.5% | 1952-1969 | [7] |
| CENAP | Germany | 13,630 | 1.1% | 98.9% | 0.2% | 0.2% | 0.4% | 1973-2026 | [8] |
| GEP | Germany | 6,479 | 2.0% | 98.0% | 0.2% | 0.1% | 0.3% | 1972-2026 | [9] |
| BUFOM | Belgium | 4,163 | 1.3% | 98.7% | 0.3% | 2007-2025 | [10] | ||
| GEIPAN | France | 3,320 | 3.2%* | 96.8% | 1.0%** | 1977-2026 | [11] | ||
| ZÁŘE | Czechia | 4,930 | 3.7% | 96.3% | 0.1% | 0.6% | 0.7% | 1992-2025 | [12] |
| UFO-Sweden | Sweden | ~22,000 | ~1% | ~99% | 0.9% | 0.1% | 1.0% | 1989-2026 | [13] |
| SUFOI | Denmark | 9,425 | 3% | 97% | 1-2% | 1% | 2-3% | 1976-2023 | [14] |
| CUFOS | USA | 1,307 | 8.6% | 92.3% | <2.8%Ω | 1976-1977 | [15] | ||
| AARO | Worldwide | 1,870§ | 3.0%√ | 97.0%√ | @ | 2024-2025 | [16] | ||
| MUFON CMS | USA | 109,696 | 32.7% | 67.3% | 4.7% | 1969-2025 | [17] | ||
| MUFON CMS | Non-USA | 27,298 | 28.5% | 71.5% | 6.6% | 1969-2025 | [17] | ||
| Canadian UFO Survey | Canada | 26,290 | 10.2%ᴪ | 89.8% | @ | 1989-2025 | [18] | ||
| NICAP | Worldwide | ~5,000 | 35% | 65% | 10.8% | 4.6% | 15.4% | 1956-1980 | [19] |
| NUFORC | Worldwide | 160,314 | 15% | 85%ɸ | @ | 1974-2026 | [20] | ||
| Memo: CE reportsΔ | Spain & Portugal | 1,177 | 53.7% | 46.3% | 11.4% | 32.7% | 44.1% | 1970-2026 | [21] |
| Symbol | Notes |
| ◊ | Except where indicated, it includes IFOs plus lack of data to evaluate reports/insufficient information (similar to GEIPAN’s “A+B+C” reports) |
| Σ | Psychological causes include unreliable reports |
| ʘ | The USAF never published a single table allocating total 12,618 cases across categories |
| (a) | BB official figures (701 unidentified) |
| (b) | BB figures as per Dr. J. Allen Hynek (587 unidentified) |
| (c) | BB figures as aggregated from the BB monthly summary sheets by Tim Printy (596 unidentified) |
| (d) | BB figures revised by Dr. J. Allen Hynek (643 unidentified) |
| (e) | BB figures revised by Tim Printy (421 unidentified) |
| (f) | BB figures as per Major Hector Quintanilla |
| (g) | BB figures as per Brad Sparks (~4,000 unidentified) |
| * | Thereof 1.0% “Unidentified phenomenon (after investigation) of Medium consistency” and 0.0% of “Strong consistency” |
| ** | Out of 1,054 reports from 2007 to 2012 |
| Ω | Includes insufficient information cases |
| § | Total collected reports up to May 30, 2025 |
| √ | Based on 1,076 reports collected in 2024–2025 |
| ᴪ | Thereof 0.7% average of “high-quality” UFO reports for 2024–2025 |
| @ | Included in the IFO class |
| ⁋ | Statistical data only for years 1953–1969, 10,304 cases (305 unidentified) |
| Ͷ | ~10,000 insufficient data. ~5,000 sufficient data (thus ~4,000 UFOs and ~1,000 IFOs) |
| ɸ | Reports not evaluated and insufficient data |
| Δ | As expected, in close encounter reports fraud and psychological causes skyrocket |
Sources
[1] USAF Fact Sheet 95-03, https://www.nsa.gov/portals/75/documents/news-features/declassified-documents/ufo/usaf_fact_sheet_95_03.pdf
[2] J. Allen Hynek (1977). The Hynek UFO Report. New York: Dell Publishing, pp. 254 and 259.pdf
[3] Tim Printy, “Blue Book raw data classification summary,”
[4] J. Allen Hynek (1977). The Hynek UFO Report. New York: Dell Publishing, p. 264
[5] Tim Printy, “Updated Blue Book Revised Classifications Summary,”
[6] Hector Quintanilla (1974, 2001). UFOs. An Air Force Dilemma. NIDS,
[7] Brad Sparks, “Comprehensive Catalog of 2,200 Project Blue Book UFO Unknowns: Database Catalog (Version 1.35),” https://www.nicap.org/bb/BB_Unknowns.pdf, and E-mail to V.J. Ballester Olmos, August 20, 2026.
[8] Hansjürgen Köhler, E-mails to V.J. Ballester Olmos, March 20, 2026 (EuroUFO List) and April 5, 2026.
[9] Danny Ammon, E-mails to V.J. Ballester Olmos, March 21, 2026 (EuroUFO List) and April 5 & 7, 2026. https://doi.org/10.5281/zenodo.10547072
[10] Wim van Utrecht, E-mails to V.J. Ballester Olmos, March 20, 2026 (EuroUFO List) and April 6 & 7, 2026.
[11] https://www.geipan.fr/en/stats (By Classification).
[12] Martin Chlebovský, E-mails to V.J. Ballester Olmos, April 4 & 7, 2026.
[13] Clas Svahn, E-mail to V.J. Ballester Olmos, April 6, 2026.
[14] Toke Haunstrup, E-mails to V.J. Ballester Olmos, April 6 & 7, 2026.
[15] Allan Hendry (1979). The UFO Handbook. Garden City: Doubleday, p. 22.
[17] Edoardo Russo (MUFON National Director for Italy), E-Mail to V.J. Ballester Olmos, April 20, 2026.
[18] Chris Rutkowski, E-mail to V.J. Ballester Olmos, April 23, 2026. https://canadianuforeport.ca/
[19] AI analysis of F. Ridge’s NICAP chrono: http://www.nicap.org/chronos/
[20] AI analysis of NUFORC databank: https://nuforc.org/subndx/?id=all
[21] Aggregate of three catalogs of UFO landing reports in Spain and Portugal: https://www.academia.edu/41625252/ENCICLOPEDIA_DE_LOS_ENCUENTROS_CERCANOS_CON_OVNIS (LANIB and NELIB), and NEWCAT (unpublished).
Acknowledgements
To Dr. Gary Posner for editing.
