We knew album sales have been bad, but this week is a testament to just how bad.

By the calculations of Billboard and the numbers released by SoundScan, last week's 4.984 million unit total sales figure is the lowest one-week sum since Nielsen began collecting sales data in 1991. That number includes digital and retail, catalog and new releases, for the seven-day period ending May 30.

Prior to '91, estimates of how many albums moved were determined by how many shipped; by those tallies, factoring in an average of albums sold to albums shipped, this weak week is comparable to an average sales week in 1973. SoundScan made those sales determinations more accurate by literally scanning each single sale, hence the name.

Then again, "Who the hell knows what weekly sales were back then," said Lou Dennis, who retired as Warner Bros. Records head of sales in 1996.

The news has renewed an ever renewing battle cry from the major record label industry: Universal Music Group Distribution president Jim Urie told the magazine this is "all the more reason why everyone in the industry should be focused on getting the U.S. Congress to introduce legislation that makes the Internet service providers our allies in fighting piracy. Piracy is getting worse and worse and the government needs to focus on that."

Sales have been steadily declining since 2000, though that year was host to the strongest sales week in the SoundScan era: 45.4 million albums were sold during the holiday shopping season in December that year.