CREATE TABLE table_203_153 (id NUMBER, "stamp issue date" CLOB, "stamp set" CLOB, "#cards" CLOB, "card set ref" CLOB, "qty. issued" NUMBER)

which stamp set had the greatest quantity issued ?
SELECT "stamp set" FROM table_203_153 ORDER BY "qty. issued" DESC LIMIT 1
SELECT "stamp set" FROM "table_203_153" ORDER BY "qty. issued" DESC FETCH FIRST 1 ROWS ONLY