Here is diversity data from Google, one of the biggest tech companies in the US / bay area: https://diversity.google/annual-report/#!#_this-years-data

Relevant numbers from "Intersectional workforce representation" section for overall Google workforce: 38.8% White men, 26.4% Asian+ men, 15.7% White women, 13.3% Asian+ women, 9.9% everyone else.

For Google workforce in tech: 41.3% White men, 31.9% Asian+ men, 13.2% Asian+ women, 9.9% White women, 7.3% everyone else.