Sorry for the later response lol. But to extend on what PoZitron said there's photo proof of 100% and it has been replicated i believe playing any amount of the multiplayer grants you the extra percent. It should also be noted that despite the game being 12 years old, the first run on the website was 3 years ago and we didn't know about 100% being possible until around a year ago just because none of us had ever played multiplayer

I'm sorry we disappointed you mr. 2nd place in fnaf 2 android/ios, legacy edition