So there are 300,000 members on the site. I assume that INTJ's are 40%. INTP and ISTJ's are 10% retrospectively.

Other Rationals such as ENTP and ENTJ 10%. NF's in total make 10%. That's 80% in total. Other types make up the rests however I didn't include.

I assume extroverted types on the board tend to be a bit more introverted.