I don't understand how the game statistics works ...

1) Total Progress = 99%, but Light World = 100% and Dark World = 80%?
2) Light World = 100%, but there's one Cotton Alley Light World Level incomplete!
3) Porcentages from Super Meat Boy Stats 1.8 are not the same porcentages that the game shows!

According to your stats:
Light levels completed + Dark levels completed + Warp levels completed + Bandages collected = 378
Max light levels + Max dark levels + Max warp levels + Max bandages count = 410
(378 / 410) * 100 = 92.195...
Total progress = 92.195 + Glitch levels completed = 98.195% (or 98.2%)
So if you complete everything it will be 106%
I'm not sure is game calculating percentage like this. This is my theory so I'm calculating like this. Save game file don't store percentages and i must calculate it myself.
Site appears to be down.
I don't know why site is down. It is not mine.