Yeah, if you think of it incorrectly in terms of a single roll. Edited By: Kay Dallben on Year 19 Day 76 17:04
At lvl 16 it is still just 12.5% chance on that roll, but the chance of Any one of those 4 rolls at levels 1,6,11,16 coming up FS Positive is what 30% is. So if you're a lvl 1 human, you have about a 30% chance of being FS by level 16. If you're a lvl 16 non-fs human about to get tested again, you still only have a 12.5% chance to be FS.
Other example: say you are a human at level 16 who has never before been tested. Your chance Ian actually the 30%, because on this test at lvl 16, if Any of the server rolls at 1,6,11,16 were successful, you will be FS.