CERT has published an Cyber security bulletin for Year 2005. Here is the snippet

This bulletin provides a year-end summary of software vulnerabilities that were identified between January 2005 and December 2005. The information is presented only as a index with links to the US-CERT Cyber Security Bulletin the information was published in. There were 5198 reported vulnerabilities: 812 Windows operating system vulnerabilities; 2328 Unix/Linux operating vulnerabilities; and 2058 Multiple operating system vulnerabilities.

Here is the link - http://www.us-cert.gov/cas/bulletins/SB2005.html

They do have a disclaimer that states that the result is aggregation of reports from various sources.