http://www.itic.ca/DIC/music/index.html
ITIC has collected Internet activity data from nearly 81,000 individuals world wide to get a better idea of P2P activity. The stats, collected between January 1st, 2003 and December 31, 2003, paint an interesting demographic picture of the P2P world. 
Q1. How many people had been downloading music files in 2003 (any Peer-to-Peer platform)?
A1. 81.5M of people, which corresponds to 4.98% of the Internet users in the World. The best P2P penetration rate was in Spain with 31% of population connected to the Internet. Other top countries were France (xx%), Belgium (26%), Venezuela (25%), Canada (23%), Argentina (22%), Netherlands (21%), Israel (19%), United States (19%), Singapore (13%), Germany (17%), Austria (16%), Morocco (14%), Portugal (12%), Sweden (10%), Mexico (8%), United Kingdom (7%), Australia (6%)…
Q2. In what countries did P2P users download the more?
A2. American P2P users downloaded 4,383,918,151 songs in 2003. Other top countries are: Germany (377M), France (xxxM), Canada (258M), United Kingdom (154M), Netherlands (87M), Japan (59M), Spain (53M), Australia (49M), Belgium (28M)…
Q3. What would best define digital piracy in 2003?
A3. We compared other facts like Software Piracy and Movie Piracy with our own records. This also involved analyzing various economical and statistical data for ~ 90 significant countries. The conclusion was that ONLY a computer with an Internet connection were common to each infringer. Whatever aspect you consider (like unemployment, poverty, literacy, amount of downloads…) will give you a completely different ranking.
Q4. What was the commercial value of digital materials illegally downloaded in 2003?
A4. This is the most sticky part of the analysis. First, remember that most of the infringers would never buy if they had to pay for what they consume. Second, the prices may vary from one country to another. Now if you consider one song to be 0.99 USD, here is an interesting ranking; this is the cumulative commercial value of [ pirated Software (BSA 2003) + pirated music (DIC 2003) ] per Internet connected capita. Russian Federation was #1 with 185 USD per Internet user. For the ~90 countries analyzed, the average Theft / Capita was 42 USD in 2003. Other top countries were Kuwait, Algeria, France, Qatar, Ukraine, Bahrain, Saudi Arabia, Paraguay, Slovenia, Morocco, Belgium, Norway, Switzerland, Nigeria, Netherlands, Hungary, Oman, Finland, Tunisia, Lebanon, Ireland, United States, Denmark, Greece, Germany, United Kingdom, Canada, China, South Africa… But the most interesting result is the value of such a worldwide digital market (excluding Movie piracy) : $ 34.3 billion in 2003.
Also interesting: A Wired interview with Wilco about how they got golden record by releasing music for free on P2P