Pray tell what table you are referring to in the link I provided.
Just looking at the 2012 field part:
~3K out of 18K is 1/6 (total)
~1.9K out of 10K is 1/5 (male)
~1K out of 8K is 1/8 (female)
Where do you get your 1/3 info from? I hope you do not show me a TRS link.