CREATE TABLE table_name_75 (mintage INTEGER, artist VARCHAR)
SELECT SUM(mintage) FROM table_name_75 WHERE artist = "steve hepburn"
ผลรวมของเหรียญกษาปณ์ของศิลปิน Steve Hepburn คือเท่าไร?
What is the sum of Artist Steve Hepburn's Mintage?