Trends in Average Heroin Purity
(1981 - 2002)

Trends in Heroin Purity at Four Purchase Levels (% by weight)
Year	< 1 gram	1 - 10 grams	10 - 200 grams	> 200 grams
1981	8	9	21	32
1982	11	13	27	52
1983	22	18	33	53
1984	26	26	41	60
1985	25	29	44	57
1986	26	28	37	51
1987	27	29	35	53
1988	32	33	47	64
1989	38	38	56	71
1990	29	31	42	62
1991	31	30	49	65
1992	37	38	55	73
1993	42	42	62	77
1994	44	45	59	74
1995	46	46	63	77
1996	37	43	55	71
1997	42	43	62	78
1998	41	45	60	76
1999	41	43	60	76
2000	42	46	63	78
2001	38	42	62	71
2002	39	41	58	70

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 12, p.69