Isn't it possible that very few children ride the bus alone in Canada? Particularly given the fact that there seems to be governmental/social pressure against this?

So the population of unsupervised children riding buses might be 10? or 100? or 1000000? we don't know.

1 in 10 would be high, though given the limited size of the dataset, possibly not very statistically relevant.

It seems doubtful that this is a very useful dataset.