Eric Schwitzgebel has a very useful post up. Here are some of the main findings:
Gender—
In the 1970s, 17% of the SED philosophy respondents were women. In the 1980s it was 22%. In the 1990s it was 27%. In the 2000s it was also 27%. So far in the 2010s it has been 28%.
Race–
Also notable is the increase from 1-2% Hispanic or Latino in the 1970s-1980s to 6.3% in the 2010s. This is still, however, well below the approximately 17% of the U.S. population that is Hispanic. It is also matched by a sharp decline in “Ethnicity not reported”, raising the possibility that it is in part a reporting effect.
The percentage of non-Hispanic Black or African American U.S. PhD recipients does not appear to have increased much if at all since the 1970s, hovering around 1.4% to 2.2%, compared to 13% of the U.S. population.
Feminist Philosophers 