How many matches did team Mumbai Indians win in 2008?
team Mumbai Indians refers to Team_Name = 'Mumbai Indians'; in 2008 refers to Match_Date like '2008%'
SELECT COUNT(T.Match_Id) FROM ( SELECT T2.Match_Id FROM Team AS T1 INNER JOIN Match AS T2 ON T1.team_id = T2.match_winner INNER JOIN Player_Match AS T3 ON T1.Team_Id = T3.Team_Id WHERE T1.Team_Name = 'Mumbai Indians' AND T2.Match_Date LIKE '2008%' GROUP BY T2.Match_Id ) T