Pro Tip: A couple of Canada's real estate boards go back and deflate a previous years sales numbers when the current year is not so rosy. TREB in 2009 and again in 2010 knocked them down the next year by over 3%.
Explanations are really not complicated or mysterious. Since these were Firm Deals when they were posted and many are commission advanced the next day we know that couple thousand annually certainly closed as Canada has an almost perfect Pending to Closed Ratio.
The answer is less nefarious than some are suggesting. "Sales Processed through the MLS in a month" does not mean sold that month. The next year Boards simply move sales from an earlier month back into the previous month which was already used in yr/yr comparison the previous mth