Fig. 3From: Seizures of illicit substances for personal use in two Italian provinces: analysis of trends by type and purity from 2008 to 2017Box plot of potency (Δ9-THC content) and purity (cocaine, heroin) by year. Median, horizontal line; boxes, 25th–75th percentiles; whiskers, 2.5th–97.5th percentiles; dots, outliersBack to article page