"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.
" The proportions of 21- to 30-year-olds who say they have ever shared needles in this way during their lifetime are 0.5% overall—0.6% of males and 0.4% of females (bottom of Table 4-1). As noted in the previous section, 1.5% of the full samples say they have ever injected a drug, so this indicates that a minority—but still a third (0.5%/1.5%)—of the people injecting any of the several drug classes mentioned in the question (heroin, cocaine, amphetamines, and/or steroids) shared a needle at some time.
"As in previous years, the proportion of young adults aged 16 to 24 taking any drug in the last year was more than double the proportion in the 16 to 59 age group, at 19.2 per cent. This proportion equates to 1.2 million young people. It is this younger age group that largely drives the trend seen in the wider group of adults aged 16 to 59.