How many times have coaches who were from CHI been awarded as NBA Coach of the Year?
CHI refers to tmID = 'CHI'; awarded Coach of the Year refers to award = 'Coach of the Year'; NBA refers to lgID = 'NBA'
SELECT COUNT(DISTINCT T2.coachID) FROM coaches AS T1 INNER JOIN awards_coaches AS T2 ON T1.coachID = T2.coachID WHERE T1.tmID = 'CHI' AND T2.award = 'NBA Coach of the Year'