http://searchengineland.com/comscore-releases-january-search-numbers-bing-gains-year-in-review-35815

"The financial analysts and investment banks publish the comScore monthly search data ahead of its public release, generally by about 24 hours. We’ll probably see comScore’s January numbers, accordingly, later today. However the numbers hit the web almost immediately because many writers/analysts/bloggers are on the investment bank mailing lists. So here, with all the usual caveats, are the comScore search numbers for January:

   * Google: 65.4 percent
   * Yahoo: 17 percent
   * Bing: 11.3 percent
...."

Also
http://www.comscore.com/index.php/Press_Events/Press_Releases/2010/2/comScore_Releases_2009_U.S._Digital_Year_in_Review
('The 2009 U.S. Digital Year in Review')