MOSCOW — Russia’s box office topped $1 billion for the first time in a full calendar year in 2011, up 20% on 2010.While ticket sales rose only 6%, the hike to $1.16 billion reflects the premium paid for tickets to 3D movies, the vast majority of which are Hollywood blockbusters. Domestic movies accounted for $170 million — 14.7% of the total — down on last year’s 15.35% share ($154 million). Top grossing movie was “Pirates of the Caribbean: On Stranger Tides” with $63.6 million, followed by “Puss in Boots” ($50.3 million) and “Transformers 3: The Dark Side of the Moon” ($45 million). The only Russian film in the top 10 was “Vysotsky: Thank God I’m Alive!” which made No.8 at $26.8 million. Russia traditionally counts the box office year from Dec. 1 to Nov. 30 to reflect the big boost given by Christmas and New Year holiday releases. By that count, B.O. in the industry year 2009-2010 was just over $1 billion. But when counted by the international standard calendar year, the figure was $963 million. The vast territory has 2,500 modern movie screens.