I question their data Almost all animation were shorts, so are probably counted twice. No shorts are shown in theaters, so I'm not sure what the hell the bottom of the graph is actually counting for the past 40 years. And porn since the 80's is all direct to video. Context, we need context!

Zarban is Reddit in disguise.

Also, short is a form, not a genre. There are short comedies, short documentaries, and short porn films. Percentages are also a problematic way to show this data, since an expansion of one type in this chart implies a contraction in another, which may or may not be the case, we simply don't know.