Among all events hold by the Student_Club in 2019, find the percentage share of events related to 'Community Service'
DIVIDE(SUM(type = 'Community Service'), COUNT(event_id)) * 100 where event_date BETWEEN' 2019-01-01' and '2019-12-31'
SELECT CAST(SUM(CASE WHEN type = 'Community Service' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(type) FROM event WHERE SUBSTR(event_date, 1, 4) = '2019'