Total jumped 22.7% from previous year.

Unit sales in 2005 topped the billion mark for the first time in the Nielsen SoundScan era, which began in May 1991. According to data released by the White Plains, N.Y.-based company, total units jumped 22.7% from the 817 million units scans in 2004. This year’s total includes 352.7 million digital track downloads, which is the main reason for the upswing.

For the year ending Jan. 1, album sales totaled almost 619 million units. That total represents a decrease of 7.2%, measured against an adjusted 52-week year where album sales are counted at 666.7 million units. When measured on an absolute basis--2004 had a 53 week year--album sales are down 9.2% from the 681.4 million units recorded in 2004.

Universal Music & Video Distribution remains the U.S. industry leader in total album market share, with 31.7%, followed by Sony BMG Music Entertainment Sales, which had 25.6%. The independent sector, collectively placed third with 18.1% followed by WEA with 15% and EMI Music Marketing, with 9.6%. Looking at current album market share, the rankings were the same, with UMVD garnering 34.8%; Sony BMG 25.6%; indies 17.5%; WEA 13.8%, and EMM, 8.3%.

In the last weeks of the year, Maria Carey’s “Emancipation of Mimi,” finished strong to score the honor of being the best-selling album of the year with scans of 4.97 million units, topping 50 Cent’s “Massacre,” which garnered 4.85 million units. Those were the only two albums that topped the 4 million mark in 2005.

Moving back to the growing digital universe, track downloads saw a major surge this year with the 352.7 million counted by SoundScan compared to 142.6 million detected in 2004. The top selling digital songs for the year were “Hollaback Girl” by Gwen Stefani and “Gold Digger” by Kenye West. Digital album sales also enjoyed explosive growth to 16.2 million units in 2005, up 194% from the 5.5 million units scanned in 2004. For the year, digital album accounted for 2.6% of all album sales.