Adele has done it again. For the second consecutive year, the British songbird's '21' has been named the best-selling album of the year in the United States, reports British newspaper the Guardian. In the year 2012, the disc sold a total of 4.41 million copies, just 25 percent less than its sales of 5.82 million units in 2011, all via the XL/Columbia record label. '21' hasn't spent a single week off the Top 40 chart since it debuted at No. 1 in March 2011.

Not many albums have reached such dizzying heights. The last best-seller for two consecutive years was Michael Jackson's monumental 'Thriller' disc, which achieved the feat in 1985. Before that, only two others albums have done it, and they're both soundtracks: 'West Side Story' in 1963 and 'My Fair Lady' in 1958.

Overall, music sales took another dip, with only 316 million total albums selling in 2012, compared to 331 million in the previous year. It's a far cry from sales figures posted even ten years ago, after the rise of Napster but before the proliferation of similar file-sharing services. Just imagine how many copies of '21' Adele would've sold in 1985.