International airplane registration codes

My initial question was: I know US registration (tail) numbers beging with “N”, what is the complete list of what counties have what tail code prefixes?

I found an answer to my initial question here:
http://www.aerospaceweb.org/question/

My followup question is:
Is this information available from the International Civil Aeronautics Org(www.icao.org)? Because I spent over an hour searching for the info.

Brian