What's the decrease rate of the game plays did David Aebischer after he got traded in 2005?
DIVIDE(SUBTRACT(SUM(GP(year = 2005), SUM(GP(year = 2006)), SUM(GP(year = 2005)) as percentage;
SELECT CAST((SUM(CASE WHEN T1.year = 2005 THEN T1.GP ELSE 0 END) - SUM(CASE WHEN T1.year = 2006 THEN T1.GP ELSE 0 END)) AS REAL) * 100 / SUM(CASE WHEN T1.year = 2005 THEN T1.GP ELSE 0 END) FROM Goalies AS T1 INNER JOIN Master AS T2 ON T1.playerID = T2.playerID WHERE T2.firstName = 'David' AND T2.lastName = 'Aebischer'