“People who need to be deported” is a very large category. Most of those people have never been charged or convicted of a criminal offence; they're just people who have been found not to have any legal status anymore, for one reason or another.
One challenge about that 34,000 number, though, is that Canada, like most countries, doesn't actually have exit controls. The government may say that there are 34,000 people subject to removal—that is, removal notices have been issued. What the government doesn't know, typically, is how many of those people have actually left of their own accord, because they don't check in with the government to tell them they're leaving.
Some number of those, for sure, will be in Canada—