That requirement is the likely reason Saskatchewan does not see the volume of cases reported in some recorded-deed jurisdictions elsewhere, where a forged signature can sometimes be registered without anyone checking identity first. A Torrens system with mandatory lawyer verification is a structurally harder target.
The exposure that remains concentrates in specific situations rather than being spread evenly: a vacant house, an inherited property still working through an estate, or an absentee owner who is not checking the mail. Those are the files worth an extra title search before listing, at a typical legal cost of $800 to $1,500.
A real frequency number would need to come from ISC or Saskatchewan's courts, and neither publishes one broken out for Saskatoon, so the honest answer is that it is rare enough not to be tracked separately, not zero. Get your hand-reviewed valuation from Joel Dyck.