From 1950 to 1970, how many coaches who received more than 1 award?
from 1950 to 1970 refers to year between 1950 and 1970; more than 3 awards refers to count(award) > 3
SELECT COUNT(coachID) FROM awards_coaches WHERE year BETWEEN 1950 AND 1970 GROUP BY coachID HAVING COUNT(coachID) > 1