THC Potency of Tested Cannabis from Federal Seizure and State and Local Eradication Samples, by Type, 1985-2014
Year Non-Domestic Samples (Federal Seizures) Domestic Samples (State and Local Eradication)
Type of Cannabis All Types1 Type of Cannabis All Types1
Marijuana Sinsemilla Marijuana Sinsemilla
Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3 Potency2 Number3
1985 3.44% 745 7.95% 12 3.48% 767 2.19% 703 7.07% 40 2.22% 845
1986 2.75% 711 8.78% 14 2.80% 753 1.95% 661 8.16% 18 1.84% 803
1987 3.16% 1,110 8.29% 17 3.20% 1,147 2.46% 441 7.69% 26 2.38% 553
1988 3.62% 1,127 8.30% 29 3.70% 1,171 2.20% 513 7.33% 69 2.56% 651
1989 3.68% 725 7.13% 29 3.78% 761 1.71% 350 6.86% 57 2.00% 511
1990 3.78% 756 9.59% 16 3.82% 788 2.09% 352 10.29% 45 2.58% 475
1991 3.18% 1,498 11.20% 29 3.26% 1,564 2.90% 651 10.10% 46 2.57% 943
1992 3.09% 2,461 9.67% 33 3.16% 2,515 3.05% 875 7.72% 43 2.96% 1,025
1993 3.67% 1,994 4.64% 5 3.65% 2,010 2.83% 1,039 5.82% 118 2.75% 1,346
1994 3.76% 2,052 6.92% 10 3.75% 2,074 2.95% 980 7.55% 94 3.02% 1,210
1995 3.95% 3,730 9.64% 17 3.98% 3,747 2.55% 701 7.26% 147 2.92% 999
1996 4.41% 1,377 11.30% 22 4.51% 1,399 2.90% 767 8.94% 146 3.48% 1,029
1997 4.93% 1,313 12.02% 18 5.03% 1,331 3.34% 954 11.50% 104 3.99% 1,119
1998 4.73% 1,298 11.88% 87 4.93% 1,335 3.36% 778 12.58% 64 3.75% 922
1999 4.36% 1,749 13.49% 55 4.63% 1,804 3.76% 691 13.31% 81 4.43% 833
2000 5.10% 1,861 12.87% 62 5.35% 1,923 3.96% 1,057 12.72% 51 4.10% 1,185
2001 5.77% 1,587 12.05% 95 6.13% 1,682 3.58% 805 7.86% 140 3.97% 1,009
2002 5.66% 1,380 14.41% 302 7.23% 1,682 3.27% 409 7.29% 226 4.29% 703
2003 5.62% 1,516 14.00% 347 7.18% 1,863 2.38% 377 7.21% 191 3.67% 625
2004 6.17% 1,418 14.06% 485 8.18% 1,903 2.55% 395 7.67% 246 4.20% 694
2005 5.92% 1,608 13.04% 681 8.04% 2,289 2.25% 354 7.78% 250 4.21% 656
2006 6.49% 1,409 13.59% 668 8.77% 2,077 1.99% 362 6.81% 364 4.15% 775
2007 7.19% 1,303 13.40% 833 9.61% 2,136 1.92% 340 7.21% 503 4.86% 883
2008 7.16% 1,054 13.08% 942 9.95% 1,997 1.82% 302 7.53% 370 4.84% 701
2009 7.13% 1,026 12.36% 1,043 9.75% 2,069 2.43% 435 7.37% 490 4.89% 962
2010 6.68% 893 12.80% 1,363 10.36% 2,256 2.79% 290 11.84% 97 4.89% 405
2011 5.60% 722 13.64% 1,615 11.13% 2,337 NA 0 NA 0 NA 0
2012 6.12% 546 14.48% 1544 12.29% 2,052 NA 0 NA 0 NA 0
2013 6.31% 262 13.64% 923 11.99% 1,185 NA 0 NA 0 NA 0
20144 6.13% 123 12.17% NA 0 NA 0 NA 0

Notes:
No data -- beginning in 2011, no domestic samples were tested.
1 The category "All Types" of cannabis tested includes ditchweed and a small number of Thai sticks.
2 These percentages, indicating potency, are based on simple arithmetic means calculated by dividing the sum of the delta-9THC concentrations of each sample by the number of seizures and are not normalized by weight of seizure.
3 Number of tested samples that yield the potency in prior column.
4 Data for 2014 are preliminary