I'll trust PHD's over a blazed-out stoner
"..
RESULTS
A total of 38,681samples of cannabis preparations were received and analyzed between January 1, 1995 and December 31, 2014. The data showed that, while the number of marijuana samples seized over the last four years has declined, the number of sinsemilla samples has increased. Overall, the potency of illicit cannabis plant material has consistently risen over time since 1995 from approximately 4% in 1995 to approximately 12% in 2014. On the other hand, the CBD content has fallen on average from approximately 0.28% in 2001 to <0.15% in 2014, resulting in a change in the ratio of THC to CBD from 14 times in 1995 to approximately 80 times in 2014.."
Https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4987131/
https://www.google.com/amp/s/amp.theguardian.com/society/2019/mar/19/high-strength-cannabis-increases-risk-of-mental-health-problems