Table 2.

Cumulative opportunity to use, use, and use given opportunity from Year 2 (age 19) through Year 8 (age 25)

	Opportunity		Use		Use Given Opportunity
	n	%wt	n	%wt	n	%
Marijuana	1081	84.8	875	61.5	872	80.7
Nonmedical Use of Prescription Stimulants	817	62.0	496	32.0	454	55.6
Hallucinogens	619	43.2	279	18.1	269	43.5
Cocaine	602	40.5	270	15.5	268	44.5
Nonmedical Use of Prescription Analgesics	579	40.1	368	23.6	304	52.5
Ecstasy	495	34.4	177	10.8	171	34.5
Nonmedical Use of Prescription Tranquilizers	393	26.0	245	14.6	226	57.7
Inhalants	238	15.5	117	7.2	104	43.7
Heroin	59	3.9	12	0.8	11	18.6

Note. Cumulative opportunity and use percentages are weighted (%_wt) to account for sampling design. N’s are unweighted. Cumulative use given opportunity reflects the amount of participants who had the opportunity to use and used the same drug during at least one study year throughout all seven years of the study.