Membership in the SFWA by Gender

I'm currently trying to hunt down some figures on the percentage of SF/F novels published on a yearly basis that are authored by women. I have not yet found those figures.

I have, however, found some startling figures on gender and membership in the Science Fiction Writers of America (SFWA) organization over the past 66 years. I'm not going to draw out any implications from these figures, but rather simply present them so that anyone who needs a quick reference can find them in one place (rather than hunt them down as I did).

Percentage of Female Members of the SFWA (1974-2015)

• In 1974, 18% of SFWA members estimated to be female*
• In 1999, 36% of SFWA members were female.*
• In 2015, 46% of SFWA members are female.**

Current Membership in the SFWA by Gender (2015)

• 47% male
• 46% female
• 7% "unspecified"

*Source: Davin, Eric Leif (2006). Partners in Wonder: Women And the Birth of Science Fiction, 1926-1965. Lanham, MD: Lexington Books. p. 69–70.

**Source: SFWA President Steven Gould (via twitter).