Calculate the average number of shipments that Zachery Hicks shipped in year 2017.
in year 2017 refers to CAST(ship_date AS DATE) = 2017; percentage = Divide (Count(ship_id where first_name = 'Zachery' AND last_name = 'Hicks'), Count(ship_id)) * 100
SELECT CAST(SUM(CASE WHEN T2.first_name = 'Zachery' AND T2.last_name = 'Hicks' THEN T1.ship_id ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM shipment AS T1 INNER JOIN driver AS T2 ON T1.driver_id = T2.driver_id WHERE STRFTIME('%Y', T1.ship_date) = '2017'