Of the 1,593 reports that had been analyzed by Project Blue Book, and we had studied and evaluated every report in the Air Force files, we had been able to explain a great many. The actual breakdown was like this:
Balloons…………………18.51%
Known 1.57
Probable 4.99
Possible 11.95
18.51
Aircraft…………………11.76%
Known 0.98
Probable 7.74
Possible 3.04
11.76
Astronomical Bodies……..14.20%
Known 2.79
Probable 4.01
Possible 7.40
14.20
Other ……………………4.21%
Searchlights on clouds, birds, blowing paper, inversions, reflections, etc.
Hoaxes……………………1.66%