> sites along similar lines

Hum. When I want such types of figures, my standard ports of call are (the above) Citypopulation.de, Wikipedia, StatCan and the CIA World Factbook.

I suspect other countries may also make their census data available in the same manner as StatCan, however I don't know any URLs offhand, as it's rare I feel the need for such knowledge about other countries beyond the level of detail provided by the above sites.