Average THC Content in Seized Marijuana Samples (1972 - 2008)

"Marijuana" is the cheaper, lower quality commercial cannabis commonly available in the United States since the 1960s. Over time (particularly with the tremendous increase in domestic production and demand for higher quality product) the THC content and general quality of commerical cannabis has been steadily increasing.

Number of Samples and Average THC Content of Seized Marijuana Year Samples Avg THC % 1972 34 1.23 1973 33 0.83 1974 113 1.34 1975 149 1.05 1976 209 1.94 1977 235 1.27 1978 128 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 1,448 2.83 1986 1,372 2.37 1987 1,551 2.96 1988 1,640 3.18 1989 1,075 3.04 1990 1,108 3.24 1991 2,149 3.09 1992 3,336 3.08 1993 3,033 3.38 1994 3,032 3.50 1995 4,430 3.73 1996 2,148 3.87 1997 2,273 4.25 1998 2,075 4.22 1999 2,450 4.18 2000 2,928 4.67 2001 2,398 5.02 2002 1,789 5.11 2003 1,893 4.97 2004 1,815 5.38 2005 1,964 5.25 2006 1,770 5.58 2007 1,635 6.11 2008 1,102 5.81

Sources: 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: ElSohly, M.A., et al "The Potency of Confiscated Marijuana, Marijuana, and Hash Oil Over a Ten-Year Period," Journal of Forensic Sciences, Volume 29, No. 2, April 1984, pp. 500-514 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 ElSohly, M.A. National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Quarterly Report, Potency Monitoring Project, Report #104, Dec 16, 2008 - Mar 15, 2009 Definition: (from ElSohly, et al) Marijuana Marijuana in the form of loose cannabis plant material with leaves, stems and seeds; includes cigarettes and those samples which cannot be described otherwise.

THC Content Overview	Hash Oil	Sinsemilla
Hashish	Thai Stick	Ditchweed