Britney Spears has sold over 31.6 million albums in the US, according to Nielsen SoundScan. Her 1999 debut has sold over 10.5 million, while her follow-up 2000’s Oops!... I Did It Again moved 9.1 million copies. 2001’s Britney sold over 4.3 million, while 2003’s In The Zone moved 2.9 million. Spears’ Blackout album, which was released in 2007 was her first not to sell one million copies shifting 991-thousand copies. She is the 16th best-selling artist since the SoundScan era began in 1991. Since then, Spears is the in fourth place among female artists behind Mariah Carey, Celine Dion and Shania Twain. Britney will release a new album in March.