When was the last year the vikings were in the super bowl?

As of the 2013 season, the Vikings have played in four Super Bowls:

Super Bowl IV, January 11, 1970: Kansas City Chiefs 23, Vikings 7

Super Bowl VIII, January 13, 1974: Miami Dolphins 24, Vikings 7

Super Bowl IX, January 12, 1975: Pittsburgh Steelers 16, Vikings 6

Super Bowl XI, January 9, 1977: Oakland Raiders 32, Vikings 14