Happy birthday, FreeBSD! You were one of the many operating systems I experimented with back in my teenage years, along with countless Linux distributions. The popularity has waned [1] but good to know it is still active :)
I'm not sure that's a good indicator. Linux shows a similar decline (try it yourself). I'd wager it's more a result of the rise of the general population coming online, including smartphones. Us geeks searches became miniscule in comparison. That's my theory, at least, and I'm sticking to it :)