The Alberta Official Statistic describes rental vacancy rates for private structures with 3 or more apartments in Alberta and its major urban centres (Calgary CMA, Edmonton CMA, Red Deer CA, Lethbridge CA, Medicine Hat CA, Wood Buffalo CA and Grande Prairie CA). An analysis was made regarding the change in rental vacancies year over year. Canada Mortgage and Housing Corporation (CMHC) conducts the Rental Market Survey (RMS) every year in April and October to estimate the relative strengths in the rental market. The survey is conducted on a sample basis in all urban areas with populations of 10,000 and more. The survey targets only privately initiated structures with at least three rental units, which have been on the market for at least three months. The data collected for a structure depends on whether it is an apartment or a row structure. The survey collects market rent, available and vacant unit data for all sampled structures. Most RMS data contained in this Alberta Official Statistic refer to privately initiated apartment structures. The survey was conducted by a combination of telephone interviews and site visits, and information obtained from the owner, manager, or building superintendent. The survey was conducted during the first two weeks of April/October, and the results reflect market conditions at that time.