Following the citations, the original source is this 2013 paper: https://pmc.ncbi.nlm.nih.gov/articles/PMC4279242/pdf/nihms580781.pdf https://pmc.ncbi.nlm.nih.g

Following the citations, the original source is this 2013 paper: https://pmc.ncbi.nlm.nih.gov/articles/PMC4279242/pdf/nihms580781.pdf https://pmc.ncbi.nlm.nih.gov/articles/PMC4279242/pdf/nihms58... The paper compares women in STEM to women outside STEM (as the baseline). However, the paper tracks a cohort of high school/college students from 1979, meaning they would've reached 35 by the 1990s.