CREATE TABLE table_42302 ("Aces" FLOAT, "Player" CLOB, "Opponent" CLOB, "Year" FLOAT, "Event" CLOB, "Sets" FLOAT, "Result" CLOB)

what's the earliest year that the wimbledon opponent was zheng jie?
SELECT MIN("Year") FROM table_42302 WHERE "Event" = 'wimbledon' AND "Opponent" = 'zheng jie'
SELECT MIN("Year") FROM "table_42302" WHERE "Event" = 'wimbledon' AND "Opponent" = 'zheng jie'