Just looking over today's release, I note that in 2016, there are average ages posted for all geographic units except census tracts, where median age is given. Previous census years used average age everywhere. What's the reasoning behind using median age for census tracts?
"Here's the reason why we moved to average age instead of median age:
In the past, Statistics Canada has been using median age as an indicator summarizing population age structure. However, we have decided to move to average age in 2016. Among others, a reason for the change is the fact that median age will not adjust as well when all baby boomers have moved to older ages. Median age does not account for shifts in the age structure at older ages, as it only divides the population in two groups of equal size. Mean age will adjust better for the changes in the age distribution at older ages, for example when boomers reach age 85 and above.
Thus, as population aging has just accelerated in Canada, we believe mean age will be more consistent with the other key messages than median age."