The feds began monitoring the potency of the nation’s pot supply in the ‘70s by drawing samples from stashes seized by law enforcement, and boy was it schwag. The percentage of THC—the main psychoactive component in cannabis—averaged from less than 1% in 1975 to just under 3% a decade later, according to the data.…
Source: Gizmodo – Why Is Weed Getting More Potent?