Average THC Content in Seized
Marijuana Samples (1972 - 2004)

Number of Samples and Average THC Content of Seized Marijuana
Year Samples Avg THC %
1972 34 1.23
1973 27 0.83
1974 63 1.34
1975 61 1.05
1976 27 1.94
1977 70 1.27
1978 68 1.47
1979 191 1.58
1980 120 1.24
1981 209 1.83
1982 435 3.07
1983 1,145 3.30
1984 1,030 3.31
1985 1,449 2.83
1986 1,370 2.37
1987 1,550 2.96
1988 1,640 3.18
1989 1,075 3.04
1990 1,108 3.24
1991 2,148 3.09
1992 3,336 3.08
1993 3,031 3.38
1994 3,024 3.50
1995 4,429 3.73
1996 2,138 3.87
1997 2,271 4.25
1998 2,075 4.22
1999 2,447 4.18
2000 2,929 4.67
2001 2,396 5.03
2002 1,788 5.11
2003 1,888 4.97
2004 939 5.81

2004 data includes samples tested through Nov 8, 2004
Source: University of Mississippi, Marijuana Potency Monitoring Project*

* The Marijuana Potency Monitoring project is sponsored by the US National Institute on Drug Abuse. The sources of the numbers quoted here are as follows:
  1. ElSohly, M.A., et al "The Potency of Confiscated Marijuana, Hashish, and Hash Oil Over a Ten-Year Period," Journal of Forensic Sciences, Volume 29, No. 2, April 1984, pp. 500-514

  2. ElSohly M.A., et al "Potency Trends of delta-9 THC and Other Cannabinoids in Confiscated Marijuana from 1980-1997, Journal of Forensic Sciences, Volume 45, No. 1, 2000, pp. 24-30

  3. ElSohly M.A. National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Quarterly Report, Potency Monitoring Project, Report #87, Aug 9, 2004 - Nov 8, 2004

Navigate to Other Available Data

THC Content Overview Hash Oil Sinsemilla
Hashish Thai Stick Ditchweed

truth: the Anti-drugwar Anti-drugwar Arsenal Accept the $1 Challenge