In 2015, among people aged 12 and older in the United States:
38,744,000 people had used cocaine at least once in their lifetime.
4,828,000 people had used cocaine in the past year.
1,876,000 people had used cocaine in the past month.
9,035,000 people had used crack at least once in their lifetime.
833,000 people had used crack in the past year.
394,000 people had used crack in the past month.

Datatable: Estimated Prevalence of Cocaine and Crack Use in the US, by Demographic Characteristics

Source

Center for Behavioral Health Statistics and Quality. (2016). 2015 National Survey on Drug Use and Health: Detailed Tables. Substance Abuse and Mental Health Services Administration, Rockville, MD, Table 1.38A and Table 1.43A.