CREATE TABLE table_20999 ("Year" FLOAT, "Mens Open" CLOB, "Womens Open" CLOB, "Mixed Open" CLOB, "Mens u20" CLOB, "Womens u20" CLOB, "Senior Mixed" CLOB, "Mens 30" CLOB, "Womens 30" CLOB, "Mens 35" CLOB, "Womens 35" CLOB, "Mens 40" CLOB, "Womens 40" CLOB, "Mens 45" CLOB, "Mens 50" CLOB)

What was the mens open when the mens u20 was Qld Country Rustlers def Southern Suns?
SELECT "Mens Open" FROM table_20999 WHERE "Mens u20" = 'Qld Country Rustlers def Southern Suns'
SELECT "Mens Open" FROM "table_20999" WHERE "Mens u20" = 'Qld Country Rustlers def Southern Suns'