See data table below with 95% confidence intervals.Smoking prevalence appeared to increase sharply with age, ranging from 0.3% of grade 7 students to 14.4% of 19-year-olds (Figure 8.3).

As noted, data up to grade 9 is provided by CSTADS, and data from CTADS is used for older youth. There may be some overlap in coverage between grade 9 students and 15-year-olds. 

Among students in grades 7-9, the pattern of increasing use by grade was consistent over time (Figure 8.4). After a substantial drop between 1994 and 2002, prevalence remained fairly low, and appears to have decreased further in the most recent years.

Over time, smoking among youth aged 15-17 declined fairly steadily overall, although there was little change in the most recent waves (Figure 8.4). Among 18- and 19-year-olds, smoking also declined overall, but less consistently, and appears to have decreased in the most recent years. The relative difference between these groups has increased over this time: in 2017, smoking prevalence among 18- and 19-year-olds was more than double that of 15- to 17-year-olds.

See data table below with 95% confidence intervals.