Table 1.

Frequency and likelihood of use of marijuana, alcohol, and tobacco products over time.

Product	Baseline	Year 1	Year 2	Year 3
	Proportion of days using, across participants
Marijuana	27.8%	31.6%	29.6%	27.9%
Alcohol	35.3%	34.1%	35.8%	34.9%
Cigarettes	38.0%	35.1%	21.8%	16.9%
E-cigarettes	11.6%	10.7%	15.3%	17.3%
	Proportion of participants with 1 or more days of use
Marijuana	58.6%	58.3%	57.3%	50.8%
Alcohol	91.6%	91.2%	90.9%	88.7%
Cigarettes	92.9%	84.4%	56.9%	46.3%
E-cigarettes	32.8%	23.7%	31.5%	36.2%