Queen's "Greatest Hits," which is already the biggest selling album of all time in the U.K., now becomes the first album to have sold more than 6 million copies in that country.

According to the U.K.'s Official Charts Company, the album -- which was released in 1981 -- still regularly sells several thousand copies per week.

In theory, about 9.5% of the U.K. population owns "Greatest Hits." (That is, if all 6 million copies are still in existence, and, multiple copies of the album are not owned by the same person.) In 2011, the U.K.'s population was 63.2 million, according to the Office for National Statistics.

The Nos. 2-5 biggest-selling albums in the U.K. are ABBA's "Gold - Greatest Hits" (5.1 million), the Beatles' "Sgt. Pepper's Lonely Hearts Club Band" (5.1 million), Adele's "21" (4.7 million) and Oasis' "What's the Story Morning Glory?" (4.6 million).

Queen has an additional title on the all-time U.K. top 10 sellers list, as "Greatest Hits II" (released in 1991) is No. 10 with 3.9 million sold.

Queen's Brian May said in a statement: "Great news, AMAZING news from the Official Charts Company! Queen's 'Greatest Hits' which was released in 1981 has passed the 6 million mark in sales, which is incredible. I just want to say thanks to everyone who has supported us through the years, we hope to continue to serve you."

In the United States, Queen's "Greatest Hits" album is certified as having sold 8 million copies, according to the Recording Industry Association of America (RIAA). It is the band's highest-selling release in the U.S.