I think it may be a difference in interpretation there. Perhaps the figures that you were looking at, as reported by the OECD, reported on the mean average as opposed to the median average. The median measures the mid-point and the mean averages everything added together and then divided.
What we've had in Canada over the past quarter century is increasing income inequality, particularly at the top end. That brings the mean average up, but the median--that's what the normal average Canadian family might have--has remained pretty much stagnant over the past quarter century.