@SW-User I'm a paramedic in the UK. I get called to about twice as many domestic incidents involving a male victim as I do to those involving a female victim. Part of the reason for that is that we only get called to a male victim if he's seriously injured. In the majority of incidents I've attended involving female victims, her injuries are superficial.
Another factor is that the police will step in to protect a woman before she's injured. It's said, with some justification, that she only has to claim her male partner looked at her in a funny way to get him arrested. Male victims, on the other hand, are left to fend for themselves and the police only step in after she's nearly (or sometime actually) killed him.
The incidence of female violence against male partners goes undocumented because the police routinely refuse to accept reports from male victims. My own husband was a victim of his former wife. He often suffered serious injuries but the police point blank refused to assist, even when there were independent witnesses. None of the incidents are recorded as crimes but that doesn't mean they didn't occur.