Only 5000 people (members) from here have run a test, and they've run 20k tests.
118,800 distinct anonymous people have run a test at least once, as counted by as much as I can to show uniqueness. Like you get a cookie and if you come back even on a new IP, you're still one person with one test history. So they account for the rest.
some more useless stats: 3.4% of tests measured over 100mbit down. 0.8% of tests measured over 200mbit down. 1.0% of tests measured over 100mbit up. 6% of tests were less than 256kbit down.