98,000 albums were released in the US in 2009; only 2.1% sold more than 5,000 copies

"A total of 98,000 albums were released in 2009, and just a handful crossed the million-mark. Perhaps more sobering, just 2.1 percent managed to cross the 5,000-mark, a group that made up 91 percent of total sales. Suddenly, fresh artists are staring at a near-zero chance of selling even modest amounts, part of a continued drizzle on DIY optimism."
Source: Data released by Nielsen Soundscan at the NARM 2010 conference, May 2010, reported by DigitalMusicNews 17th May 2010
Earlier - 105,000 released in 2008; only 6,000 sold more than 1,000 copies (which is consistent with the 2009 figure, but also frustratingly different...)