Serum androgens and sex hormone-binding globulins in relation to lifestyle factors in older African-American, white, and Asian men in the United States and Canada
cebp.aacrjournals.org/cgi/reprint/4/7/735
Interesting to note that the average age of study participants is between 60-70 yrs old, and their Total T levels are ~ 450-500 ng/dl (similar to where many guys end up after Finasteride, or lower).
Study also lists levels for Free, Bioavailable Testosterone, DHT, SHBG etc…