There are a variety of data sources for population. The UN provides data for member states from 1950 onwards in 5 year intervals. It is available at:
http://esa.un.org/unpp/index.asp?panel=1
For simplicity, it might make sense to use the population value that precedes the year of the games i.e. the 1950 value for the 1952 games. Has anyone got any other good sources?
 15:37, 17 Aug 2004 (UTC)