Database: ice_hockey_draft
Question: Among all players drafted by the Toronto Maple Leafs, identify the percentage who are from Eastern Europe.
SQL: SELECT CAST(COUNT(CASE WHEN nation IN ('Belarus', 'Czech Rep.', 'Slovakia', 'Ukraine') THEN ELITEID ELSE NULL END) AS REAL) * 100 / COUNT(ELITEID) FROM PlayerInfo WHERE overallby = 'Toronto Maple Leafs'