According to public health authorities, most of the cases of HIV infection were due to abuse of oxymorphone tablets, which were dissolved and then injected. Authorities in the United States have indicated that the medical consequences of cannabis abuse continue to grow: the percentage of emergency room visits and admissions to treatment reported as cannabis-related increased from 6.9 per cent in 1993 to 17.5 per cent of all drug-related admissions in 2012. At the same time, surveys conducted in the North American region indicate that among young people there is a low perception of risk associated with regular cannabis use. In the United States, the Monitoring the Future Survey showed that 60 per cent of twelfth grade students (aged 17-18 years) do not consider regular cannabis use to be harmful.