As much as I love rock radio, my local station drops the ball in one major area: they have a strong, obvious bias towards male vocalists. I haven't applied science to the problem, but I'd be surprised if female-fronted bands get more than 5% of the airtime. Factor in male/female duets and you might hit 7%.
That's a generous estimate.
The only (highly dubious) plus side to it all is that the female-fronted bands that do hit the airwaves tend to stand out. That's the case with the Pretty Reckless, whose song "Heaven Knows" has enjoyed a lot of play recently. I love it and end up with it stuck in my head on a regular basis, so I thought I'd share it with y'all today.