While the Call of Duty franchise has enjoyed year-over-year growth in terms of worldwide sales, numbers released this week for the UK tell a different story for that particular region. According to the UK's Entertainment Retailers Association, Modern Warfare 3 moved 2,814,298 units between launch on November 8 and December 31, 2011, while Call of Duty's 2010 entry, Black Ops, sold 3,266,298 across the same holiday sales period in the previous year.

That's a decline of 452,000 units from Treyarch-developed Black Ops in 2010 to Infinity Ward/Sledgehammer Games-developed Modern Warfare 3 in 2011, though the latter was the fastest entertainment property in history to reach $1 billion in sales. As MCV points out, FIFA sales were also in decline in the UK, with nearly 200K fewer copies sold during 2011 than in 2010. All that said, let's not lose any sleep over the declines -- both CoD and FIFA's 2011 entries sold in the many millions in just the UK, let alone worldwide.