Global Online Population
An important data resource is a collection of the latest statistics on Internet users for countries around the world. CyberAtlas maintains an updated list and compares it to regional growth patterns and other projections for accuracy.
The population statistics of the countries listed is taken from the CIA's World Factbook. The number of active users is tracked by the Nielsen//NetRatings service, which account for more than 90 percent of the world's Internet users. The number of active users is an estimate of the number of people that actually go online in a given month.
See the site link for the complete data and source of statistical information from each country.