FINDINGS: 5% of UFO sightings are inexplicable and the best hypothesis to explain them is the extraterrestrial hypothesis (ETH).
The study was carried out over several years by an independent group of mostly former "auditors" at the Institute of Advanced Studies for National Defence, or IHEDN, a high-level French military think-tank, and by various other experts.
The group was responsible for the 'COMETA Report' (1999) on UFOs and their possible implications for defence in France. The report concluded that about 5% of the UFO cases they studied were utterly inexplicable and the best hypothesis to explain them was the extraterrestrial hypothesis (ETH). The authors also accused the United States government of engaging in a massive cover-up of the evidence.
Source: Wikipedia, COMETA