I'm not sure if anyone asked it before, but a professional statician crunched the numbers, and it turns out, almost one fifth of sexual content in a selection of popular ero-manga is rape, with Angel Club being the worst offender.

The above picture was uploaded to twitter, which you can see HERE. A presentation at the yearly Nico Nico Chokaigi has revealed the relative percentages of consensual and non-consensual sexual content in nineteen popular ero-manga magazines. 

Here's how those numbers break down in plain English:

Angel Club: 76% forced, 24% consensual
Comic Kuriberon: 50/38
Magazine Siberia: 44/56
Comic Yumutensei: 31/69
Comic Taka: 21/79
Men’s Gold: 21/79
Comic X-Eros: 17/83
Comic Ansurium: 17/83
Comic Aun: 13/81
Comic Europa: 11/89
Web Maga Bangaichi: 10/90
Comic ExE: 10/86
Comic Kairakuten: 10/86
Penguin Club: 8/83
Action Pizatsu: 8/92
Comic Naman: 6/94
Comic Lo: 5/90
Comic Bavel: 5/95
Magnum X: 0/100
Total: 19/79

Let's just take a moment to appreciate how titles can be misleading. Angel Club is 76% forced, and Magnum X is 0% forced. Let's also take a moment to appreciate that at least some of those numbers don't add up to 100%. Perhaps there's a percentage of error, or there was some ambiguity on whether or not the content was forced, so it was left out.