Psychedelia.dk

"Shulgin puts his own figure above 4,000" (psychedelic experiences)
src: http://mdma.net/alexander-shulgin/dr-ecstasy.html

PIHKAL indicates that he's been sampling compounds on himself since the mid 1940s so we'll say 1945.

1945 - 2005 = 60 years of sampling!
= 66.6 samplings each year
= 5.5 samplings each month