You'll need about 107+ games to get below 10%. (99% sure this number is wrong in every way)
His profile says 28 games played and 3 times booted (10.7%)
How is that 99% certainty not 100% ;)
2 more games without getting booted gets him on 3 out of 30, which is exactly 10%. All games after that make him go below the 10% (unless he gets booted again)