Among all the tweets with a positive sentiment, what is the percentage of those posted by a male user?
positive sentiment refers to Sentiment > 0; male user refers to Gender = 'Male'; percentage = Divide (Count(TweetID where Gender = 'Male'), Count (TweetID)) * 100
SELECT SUM(CASE WHEN T2.Gender = 'Male' THEN 1.0 ELSE 0 END) / COUNT(T1.TweetID) AS per FROM twitter AS T1 INNER JOIN user AS T2 ON T1.UserID = T2.UserID WHERE T1.Sentiment > 0