"For crack cocaine offenders, the most common functions for offenders were Street-Level Dealer (47.0%) and Wholesaler (27.9%). The least common functions were Mule (0.2%), Supervisor (0.5%), High Level Supplier/Importer (0.5%), and Manager (0.7%).667
"Over three-quarters (77.8%) of Street-Level Dealer offenders were convicted of an offense carrying a mandatory minimum penalty. Wholesaler offenders were convicted of an offense carrying a mandatory minimum penalty at a rate of 93.5 percent in crack cocaine cases. High-Level Supplier/Importer, Organizer/Leader, Manager, Supervisor, and Mule offenders were convicted of statutes carrying a mandatory minimum penalty in all cases."

Source

"Report to Congress: Mandatory Minimum Penalties in the Federal Criminal Justice System" (Washington, DC: US Sentencing Commission, October 2011), p. 203.
http://www.ussc.gov/Legislati…
http://www.ussc.gov/Legislati…