"In the thirteen-year (2004–2016) combined sample of young adults aged 21–30, 1.5% report having ever used any drug by injection not under a doctor’s orders, and 0.5% reported doing so on 40 or more occasions (Table 4-1a). Thus, about 1 in every 67 respondents has ever used an illicit drug by injection, and about 1 in every 200 respondents reports an extended pattern of use as indicated by use on 40 or more occasions. There is a fair-sized gender difference -- 2.3% of males vs. 0.9% of females indicate ever injecting a drug.

"Marijuana, the most widely used of the illicit drugs, did not show any significant change in annual prevalence this year in any of the three grades, nor in the three grades combined. After rising for several years, the annual prevalence of marijuana has more or less leveled out since about 2010.

"• Marijuana is by far the most widely used illicit drug. Nearly half of all 12th graders (45%), nearly one third of 10th graders (31%), and over one in seven 8th graders (14%) reported some marijuana use in their lifetime. Among 12th graders, 37% reported some use in the past year, and 23% reported some use in the past month. Among 10th graders, the corresponding percentages were 26% and 16%, respectively, and among 8th grade students, 10% and 5.5%.

"Annual marijuana prevalence peaked among 12th graders in 1979 at 51%, following a rise that began during the 1960s. Then use declined fairly steadily for 13 years, bottoming at 22% in 1992—a decline of more than half. The 1990s, however, saw a resurgence of use. After a considerable increase (one that actually began among 8th graders a year earlier than among 10th and 12th graders), annual prevalence rates peaked in 1996 at 8th grade and in 1997 at 10th and 12th grades. After these peak years, use declined among all three grades through 2007 or 2008.

"• In 2017, 46% of 8th graders and 63% of 10th graders thought that cigarettes would be fairly easy or very easy for them to get if they wanted some. In 2017 for the first time we asked about availability of cigarettes among 12th graders; 78% reported they would be fairly easy or very easy to get. A growing interest among state and local governments to increase the minimum age to 21 for the purchase of tobacco products suggests that availability may decrease for this age group in the coming years.

Data Table of Estimated 30-Day Prevalence of Use of Various Drugs for Young People in the US in Grades 8, 10, and 12 Combined, 1998 through 2016, According to the Monitoring The Future Survey

"Crack cocaine use spread rapidly from the early to mid-1980s. Still, among 12th graders, the use of crack remained relatively low during this period (3.9% annual prevalence in 1987). Clearly, crack had quickly attained a reputation as a dangerous drug, and by the time of our first measurement of perceived risk in 1987, it was seen as the most dangerous of all drugs. Annual prevalence dropped sharply in the next few years, reaching 1.5% by 1991, where it remained through 1993.