Interestingly I worked in a DNA sequencing centre - so very STEM related. Around 50% of the staff worked in the wet lab and 50% in the bioinformatics part. Around 50% of the staff were female and the vast majority of them worked in the wet lab part. Most of the males worked in the bioinformatics side. So even within STEM there appear to be some clear divisions with the disciplines that attract females / males.