How many events of the Student_Club did Sacha Harrison attend in 2019?
events attended in 2019 refers to YEAR(event_date) = 2019
SELECT COUNT(T1.event_id) FROM event AS T1 INNER JOIN attendance AS T2 ON T1.event_id = T2.link_to_event INNER JOIN member AS T3 ON T2.link_to_member = T3.member_id WHERE T3.first_name = 'Sacha' AND T3.last_name = 'Harrison' AND SUBSTR(T1.event_date, 1, 4) = '2019'