Record Subscriber Additions of Approximately 2.2 Million in 2005 - Satellite Radio Market Share Leader For The Fourth Quarter With More Than 1.1 Million Subscriber Additions - SIRIUS Expects To End 2006 With More Than 6 Million Subscribers. SIRIUS subscriber base increased 190% in 2005 to 3,316,560 at year end. SIRIUS added a record 2,173,302 subscribers during the year. For the fourth quarter, SIRIUS was the market share leader in terms of new satellite radio subscriber additions, adding 1,142,640 net new subscribers during the quarter. This was an increase of 138% over the year-ago quarter and the company's best ever quarterly gain.