Comment by ithkuil

Some other comment in this discussion claims that if you nudged the total count integer +-1 you'll never hit 52.20000000% exactly hinting at the possibility that they choose 52.2% exactly, then computed the total counts which would be a non-integer and then just rounded that.

Once re-computing the percentage from that number you end up with the slightly less round-looking 51.1999971%.