This is cargo cult statistics. He's seen the words used before and has a surface-level idea of the context, but no understanding of how they function or the concepts behind them.

For Trump to have "34 times" the felonies, Obama would need one. But if that were the case it would still be 0.756 per-capita for white presidents and 1.0 per-capita for black because there have been 45 white presidents. Now if you said, "since 2008" it would still be wrong, but then we could at least say funny things like "on average, white presidents since 2008 have had 17 felony convictions per-capita," implying that half are Biden's.