Tentatively updated. Will investigate further later. 3.1 number comes from an odd data-set.
http://www.niehs.nih.gov/research/atniehs/labs/epi/studies/eps/question/index.cfm
Tentatively updated. Will investigate further later. 3.1 number comes from an odd data-set.
http://www.niehs.nih.gov/research/atniehs/labs/epi/studies/eps/question/index.cfm