![](media/image1.wmf){width="9.0in" height="5.7243055555555555in"}

![](media/image2.wmf){width="9.30625in" height="6.002777777777778in"}

![](media/image3.wmf){width="8.625in" height="5.756944444444445in"}

![](media/image4.wmf){width="8.80625in" height="6.138888888888889in"}

![](media/image5.wmf){width="8.18125in" height="6.227083333333334in"}

![](media/image6.wmf){width="8.05625in" height="6.573611111111111in"}

![](media/image7.wmf){width="8.75in" height="6.252777777777778in"}

![](media/image8.wmf){width="8.68125in" height="6.627777777777778in"}

![](media/image9.wmf){width="8.43125in" height="6.472222222222222in"}

**Table 10**

**Definitions of Quantity Level Ranges & Number of Observations**

**When Seizure Data Are Included**

![](media/image10.wmf)

####### Table 11

**The Mean and Median Purity for Powder Cocaine**

**When Seizures Are Included**

  ------- ------- -------- ------- -------- ------- -------- ------- --------
          ≤ 10             10-50            50 -             \> 750  
          Grams            Grams            750              Grams   
                                            Grams                    

  Year    Mean    Median   Mean    Median   Mean    Median   Mean    Median

  1981    0.49    0.46     0.52    0.50     0.70    0.76     0.85    0.88

  1982    0.50    0.45     0.52    0.50     0.75    0.83     0.88    0.90

  1983    0.57    0.54     0.62    0.63     0.80    0.87     0.91    0.92

  1984    0.58    0.56     0.65    0.67     0.78    0.85     0.89    0.91

  1985    0.53    0.49     0.61    0.61     0.72    0.80     0.85    0.89

  1986    0.62    0.63     0.71    0.78     0.80    0.87     0.88    0.90

  1987    0.70    0.80     0.77    0.84     0.83    0.88     0.88    0.89

  1988    0.74    0.83     0.79    0.85     0.81    0.86     0.86    0.89

  1989    0.71    0.79     0.73    0.81     0.77    0.84     0.83    0.87

  1990    0.58    0.58     0.60    0.60     0.67    0.73     0.79    0.86

  1991    0.68    0.76     0.70    0.76     0.74    0.82     0.84    0.88

  1992    0.69    0.78     0.72    0.79     0.76    0.83     0.83    0.88

  1993    0.68    0.75     0.67    0.72     0.75    0.82     0.83    0.87

  1994    0.69    0.78     0.70    0.77     0.76    0.82     0.84    0.86

  1995    0.66    0.73     0.68    0.73     0.71    0.78     0.82    0.86

  1996    0.68    0.75     0.69    0.74     0.73    0.80     0.83    0.86

  1997    0.65    0.72     0.67    0.72     0.70    0.78     0.82    0.85

  1998    0.68    0.76     0.68    0.75     0.71    0.79     0.80    0.83

  1999    0.63    0.68     0.62    0.66     0.66    0.72     0.77    0.81

  2000    0.58    0.59     0.56    0.59     0.59    0.65     0.73    0.78

  2001    0.56    0.59     0.53    0.55     0.58    0.65     0.71    0.74

  2002    0.62    0.68     0.60    0.65     0.62    0.68     0.74    0.78

  2003    0.65    0.74     0.60    0.65     0.67    0.74     0.79    0.84
  ------- ------- -------- ------- -------- ------- -------- ------- --------

\* 2003 purities are based on information from only the first two
quarters of the year, and thus are likely to be updated in future
reports.

Source: System to Retrieve Information on Drug Evidence (STRIDE).

Prepared by: RAND Corporation, February 2004.

**Table 12**

**The Mean and Median Purity for Heroin When Seizures Are Included**

  ------- ------ -------- ------- -------- ------- -------- ------- --------
          ≤ 1             1-10             10 -             \> 200  
          Gram            Grams            200              Grams   
                                           Grams                    

  Year    Mean   Median   Mean    Median   Mean    Median   Mean    Median

  1981    0.08   0.04     0.09    0.04     0.21    0.04     0.32    0.22

  1982    0.11   0.05     0.13    0.04     0.27    0.07     0.52    0.67

  1983    0.22   0.10     0.18    0.07     0.33    0.21     0.53    0.60

  1984    0.26   0.13     0.26    0.14     0.41    0.41     0.60    0.62

  1985    0.25   0.14     0.29    0.18     0.44    0.45     0.57    0.57

  1986    0.26   0.16     0.28    0.18     0.37    0.34     0.51    0.50

  1987    0.27   0.17     0.29    0.18     0.35    0.30     0.53    0.48

  1988    0.32   0.25     0.33    0.27     0.47    0.48     0.64    0.70

  1989    0.38   0.35     0.38    0.38     0.56    0.59     0.71    0.81

  1990    0.29   0.22     0.31    0.24     0.42    0.39     0.62    0.68

  1991    0.31   0.23     0.30    0.22     0.49    0.51     0.65    0.69

  1992    0.37   0.31     0.38    0.35     0.55    0.55     0.73    0.82

  1993    0.42   0.35     0.42    0.35     0.62    0.66     0.77    0.84

  1994    0.44   0.38     0.45    0.40     0.59    0.64     0.74    0.82

  1995    0.46   0.38     0.46    0.42     0.63    0.66     0.77    0.86

  1996    0.37   0.30     0.43    0.40     0.55    0.57     0.71    0.80

  1997    0.42   0.33     0.43    0.37     0.62    0.68     0.78    0.84

  1998    0.41   0.33     0.45    0.42     0.60    0.62     0.76    0.83

  1999    0.41   0.34     0.43    0.41     0.60    0.63     0.76    0.82

  2000    0.42   0.35     0.46    0.47     0.63    0.67     0.78    0.84

  2001    0.38   0.31     0.42    0.40     0.62    0.67     0.71    0.81

  2002    0.39   0.35     0.41    0.38     0.58    0.60     0.70    0.80

  2003    0.37   0.32     0.40    0.37     0.53    0.55     0.70    0.75
  ------- ------ -------- ------- -------- ------- -------- ------- --------

\* 2003 purities are based on information from only the first two
quarters of the year, and thus are likely to be updated in future
reports.

Source: System to Retrieve Information on Drug Evidence (STRIDE).

Prepared by: RAND Corporation, February 2004.

**Table 13**

####### The Mean and Median Purity for d-Methamphetamine 

**When Seizures Are Included**

  ------- ------- -------- -------- -------- ------- -------- ------- --------
          ≤ 10             10-100            100 -            \> 500  
          Grams            Grams             500              Grams   
                                             Grams                    

  Year    Mean    Median   Mean     Median   Mean    Median   Mean    Median

  1981    0.45    0.36     0.39     0.31     0.56    0.63     0.72    0.75

  1982    0.56    0.54     0.44     0.39     0.50    0.50     0.48    0.43

  1983    0.50    0.47     0.45     0.38     0.51    0.54     0.22    0.14

  1984    0.49    0.44     0.46     0.43     0.43    0.34     0.60    0.43

  1985    0.50    0.46     0.51     0.48     0.56    0.56     0.63    0.83

  1986    0.59    0.58     0.57     0.60     0.58    0.61     0.68    0.73

  1987    0.65    0.70     0.57     0.56     0.61    0.65     0.65    0.78

  1988    0.67    0.75     0.61     0.64     0.65    0.68     0.70    0.71

  1989    0.65    0.70     0.58     0.57     0.61    0.65     0.68    0.79

  1990    0.49    0.41     0.43     0.32     0.41    0.31     0.47    0.40

  1991    0.51    0.41     0.48     0.35     0.49    0.39     0.44    0.32

  1992    0.67    0.80     0.57     0.57     0.71    0.85     0.74    0.91

  1993    0.70    0.87     0.64     0.73     0.74    0.89     0.80    0.92

  1994    0.73    0.88     0.69     0.85     0.77    0.89     0.83    0.93

  1995    0.66    0.83     0.60     0.66     0.66    0.82     0.74    0.88

  1996    0.60    0.69     0.47     0.36     0.49    0.38     0.52    0.41

  1997    0.59    0.54     0.50     0.40     0.52    0.43     0.53    0.45

  1998    0.42    0.29     0.27     0.17     0.23    0.18     0.26    0.19

  1999    0.46    0.33     0.31     0.21     0.26    0.20     0.29    0.22

  2000    0.47    0.35     0.34     0.24     0.29    0.21     0.35    0.23

  2001    0.51    0.44     0.40     0.25     0.33    0.22     0.45    0.28

  2002    0.52    0.48     0.42     0.29     0.37    0.23     0.49    0.32

  2003    0.59    0.62     0.53     0.53     0.45    0.31     0.64    0.76
  ------- ------- -------- -------- -------- ------- -------- ------- --------

\* 2003 purities are based on information from only the first two
quarters of the year, and thus are likely to be updated in future
reports.

Source: System to Retrieve Information on Drug Evidence (STRIDE).

Prepared by: RAND Corporation, February 2004.