Updated with PLAYED and WIN% columns. PLAYED is the percentage of seasons you've participated in, calculated based on a total of 320 possible points (10 for a TWL win, 3 for a TWDT win, 3 for a Cup win). WIN% is the percentage of points you captured in seasons you played (with half credit for runner-up).
This new method better rewards players who may have played fewer seasons but performed exceptionally well when they did (I noticed mega89 had slipped to 5.)