"Approximately two-thirds (66.1%, n=15,831) of the 23,964 drug offenders in fiscal year 2010 were convicted of an offense carrying a mandatory minimum penalty. More than one-quarter (28.1%, n=4,447) of drug offenses carrying a mandatory minimum penalty involved powder cocaine, followed by crack cocaine (24.7%, n=3,905), methamphetamine (21.9%, n=3,466), marijuana (17.2%, n=2,725), heroin (6.9%, n=1,098) and other drugs (1.1%, n=172). See Figure 8-1.
"The application of mandatory minimum penalties varies greatly by the type of drug involved in the offense. For example, in fiscal year 2010, a mandatory minimum penalty applied in 83.1 percent (n=3,466) of drug cases involving methamphetamine. In contrast, such a penalty applied in less than 45 percent (n=2,725) of marijuana cases. With respect to other drugs (such as PCP and LSD), such a penalty applied in 11.4 percent (n=172) of cases."

Source

"Report to Congress: Mandatory Minimum Penalties in the Federal Criminal Justice System" (Washington, DC: US Sentencing Commission, October 2011), p. 153.
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