Probably at the same rate that whites were published.

I know of no easy way to find the facts about these authors. But we have their stories. They can be read & considered & analyzed. We can find queer themes in stories that eluded previous generations of readers, for example.

Martin would have you believe the history of science fiction is written, and, surprise, it's a shower of white male mfers.

It's not. The history of sf is wide-open--undocumented--uncharted. Heavily white? Maybe. But just as likely to be populated with BIPOCs as just whites.

The history of the genre isn't the story of white male writers. It never was. It's the history of all of us.