16% having personally seen something seems a bit high for your logic [0]. Granted, I don't have data for the "close encounters," so most of these will be distant or unclear, short observations with prosaic explanations.
I've never seen anything myself, but anecdotally, a group of sane family members did (a close encounter, at that) circa 1970, long before the secret military jet angle would have any credibility. Apparently more than half of people can share a similar personal or family anecdote.
[0] https://www.syracusenewtimes.com/ufos-aliens-and-abductions-...