Although straights beat them by far in raw numbers, lesbians beat everyone in percentages. Gays guys generally don't beat the shit out of each even though men are supposed to be the more violent ones.

Probably the reason lesbians are higher is they don't have a guy (whether it be current boyfriend, ex, friendzoned guy, etc.) to do the fighting for them. Women think and want to carry out violence just as often as men do, but even the most stubborn feminist cannot overrule their subconscious telling them they aren't built for it. That's why a ton of women get men to do it for them. In addition, most women will only get into fights with guys if they think the guy will absolutely not retaliate.

Lesbians do not have the same repertoire built with as many guys and so have less people to manipulate to do the fighting for them. They have to take action with their own hands and against another woman they don't have the subconscious aspect telling them to avoid the fight.