Calculate the win rate of the toss-winners in 2012.
in 2012 refers to Match_Date like '2012%'; win rate refers to DIVIDE(COUNT(Toss_Winner = Match_Winner), COUNT(Match_Date like '2012%'))
SELECT CAST(SUM(CASE WHEN Toss_Winner = Match_Winner THEN 1 ELSE 0 END) AS REAL) / SUM(CASE WHEN Match_Date LIKE '2012%' THEN 1 ELSE 0 END) FROM `Match`