CREATE TABLE table_15496 ("Year" FLOAT, "Competition" CLOB, "Venue" CLOB, "Position" CLOB, "Notes" CLOB)

When did a Position of 21st (q) happen?
SELECT "Year" FROM table_15496 WHERE "Position" = '21st (q)'
SELECT "Year" FROM "table_15496" WHERE "Position" = '21st (q)'