Only thing I can think of that could change the outcome of your analysis is that you can't count with SP inflation when divesting. It's called divesting also cause you are withdrawing vests, and they don't inflate themselves. Which means for an account that doesn't curate or post and receive vests from the daily pool divided in SB/Steem/SP, their divesting % will remain the same, steem will inflate during the whole time but the % of divesting will be constant thuse making every steempower divest bigger than the previous one.