You'll have to ask Statistics Canada how exactly those data were collected. That's why we created these data. It's true that it'll be difficult to disentangle what other drugs might have been present in that person's system, but what is irrefutable is that in those circumstances the drug that was most present consistently was cannabis. No other drug was more present than cannabis in drug-related driving occurrences.
On September 12th, 2017. See this statement in context.