This is because of the amnesty? The 1.2 million registered weapons go back to 1995, apparently, from what I'm reading here, and half of those haven't been re-registered since then. Is that accurate? I'll ask the Auditor General's Office.
Evidence of meeting #16 for Public Accounts in the 39th Parliament, 1st session. (The original version is on Parliament’s site, as are the minutes.) The winning word was registry.
A recording is available from Parliament.