A decrease in sales does not necessarily mean a decrease in property values

The statistics compiled monthly by the Real Estate Board of Greater Vancouver show that a decrease in monthly sales does not necessarily result in a decrease of property values even though this seems to be contrary to economic principles. Click on the above link and scroll down to "Download the complete stats package by clicking here".
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On pages two and three of the stats package named "MLS home price index" is a list of the percentage change of the benchmark price for each area by property type. The benchmark price is the estimated sale price of a typical property in each market. The percentage change is calculated for different time periods - 1 , 3 and 6 months as well as 1, 3 and 5 years.