Again, read the numbers of abortions in every single country the year before liberalization and the year after. Or, if you prefer, ten years before and ten years after. The notion that "liberalization" mean less abortions is prima facie nonsensical, a logical aberration, something utterly demanding an impressive explanation, something that wasn't given at all.
Now, if you "add" other variables like healthcare, education, economic issues, etc., then it makes sense. Notice however how these very important variables are logically separated from abortion law. You can have a country with a proper single payer healthcare, good sex-ed, a good economic outlook and so on, and still not be liberal about abortion. Prima facie, it's quite obvious that in such a country the abortion numbers would be even lower than in Canada.