Trends in Average Methamphetamine Purity
(1981 - 2002)

Trends in Methamphetamine Purity at Four Purchase Levels (% by weight)
Year	< 10 grams	10 - 100 grams	100 - 500 grams	> 500 grams
1981	45	39	56	72
1982	56	44	50	48
1983	50	45	51	22
1984	49	46	43	60
1985	50	51	56	63
1986	59	57	58	68
1987	65	57	61	65
1988	67	61	65	70
1989	65	58	61	68
1990	49	43	41	47
1991	51	48	49	44
1992	67	57	71	74
1993	70	64	74	80
1994	73	69	77	83
1995	66	60	66	74
1996	60	47	49	52
1997	59	50	52	53
1998	42	27	23	26
1999	46	31	26	29
2000	47	34	29	35
2001	51	40	33	45
2002	52	42	37	49

Source: Office of National Drug Control Policy
The Price and Purity of Illicit Drugs: 1981 Through the Second Quarter of 2003.
November 2004 (Publication Number NCJ 207768), Table 13, p.70