We got nerd sniped at almost the exact same time, but approached this in very different ways. I applaud your practical approach, but based on what I calculated, you should stop now. It will never reach 99.999%
There are 9592 prime numbers less than 100,000. Assuming the test suite only tests numbers 1-99999, the accuracy should actually be only 90.408%, not 95.121%
The density of primes can be approximated using the Prime Number Theorem: 1/ln(x).
Solving 99.9995 = 100 - 100 / ln(x) for x gives e^200000 or 7.88 × 10^86858. In other words, the universe will end before any current computer could check that many numbers.
We got nerd sniped at almost the exact same time, but approached this in very different ways. I applaud your practical approach, but based on what I calculated, you should stop now. It will never reach 99.999%