The "High School Musical" phenomenon has entered the record books, again.

More than six million combined physical and digital copies of "High School Musical 2" (Walt Disney Records/Universal/EMI) were shifted worldwide en route to becoming the best-selling album last year, according to the IFPI's newly-published annual handbook.

The soundtrack set repeated the feat of its predecessor, "High School Musical," which was the world's best-selling album in 2006, the IFPI notes, marking the first time that the same act has topped the global chart in consecutive years. The trade body began tracking the global best sellers in 2001.

The rise and rise of "High School Musical" is one of many findings explored in the IFPI's 2008 edition of "Recording Industry In Numbers," distributed today.

The IFPI also points to an overall healthy sales trend for the world's biggest albums. Aggregated sales of the top 50 albums rose by 3% in 2007, coming on the back of a decline in 2006, while the combined top 10 albums in 2007 grew by a "healthy" 15%, the IFPI explains.

The state of the global recorded music industry, however, is not as rosy, with the market dropping 8% year-on-year for a trade value of $19.4 billion.

The figure takes into account physical and digital formats, plus record company revenue from performance rights licensing. Digital sales pushed toward the $3 billion mark, but were unable to counter the continuing decline in physical product. Digital formats saw growth of 34% to $2.87 billion, while physical product diminished 13% to 15.87 billion.

The list of the top 10 markets has a familiar look to it, with only one change as Mexico is replaced at No. 10 by the Netherlands. The top 10 markets are, respectively, the United States, Japan, the United Kingdom, Germany, France, Canada, Australia, Italy, Spain and the Netherlands.

Only two of the two 20 markets registered growth: No. 17-ranked South Africa (+2%) and No. 20-ranked India (+12%), while the Japanese market was flat. The remaining 17 countries saw their respective recorded music markets shrink.