I would try to assign a date with which site these swings occur. You keep a Poker Journal-yes? If not, just get a spiral notebook and log your sesions/overall stats with any personal internal comments. Like: didn't play well-just broke up with girlfriend; was in the zone after tourney win; etc....

What can be uncovered is: what happened at ~7k; ~9k; ~16k; ~18k hands. Was it a different site? Was it a lack of quality sleep? Flu? At 18k, your trendline starts to flatten with some broad swings after. Overconfident/too loose? Etc... You get the idea.
Anyway, overall your trendline is definately in the positive.

All the best