The percentage of population who are drug abusers reported to the Central Registry of Drug Abuse (CRDA), based on mid-year estimate of population. The definition of drug abuse is the taking of drugs which harms or threatens to harm the physical, mental or social well-being of an individual, in doses above or for periods beyond those normally regarded as therapeutic. Reported drug abusers refer to number of persons (all ages) known to the CRDA as at end of year.