CMHC does not publish a statistic if its reliability is too low or if publication of a statistic would violate confidentiality rules. The ability to publish an estimate is generally determined by its statistical reliability. As indicated earlier, CMHC currently uses the coefficient of variation (CV).
A letter code representing the statistical reliability (i.e., the coefficient of variation (CV)) for each estimate is provided to indicate the data reliability. CV of an estimate is defined as the ratio of the standard error of the estimate to the estimate itself and the CV is generally expressed a percentage. For example, let the average rent for one bedroom apartments in a given CMA be x̄ and its standard error be σ x̄. Then the Coefficient of Variation is given by CV = σx̄ / x̄.