CREATE TABLE table_21173 ("Year" FLOAT, "Tournaments played" FLOAT, "Cuts made" FLOAT, "Wins" FLOAT, "Best finish" TEXT, "Earnings  (  $  ) " FLOAT, "Money list rank" TEXT)

what was Casey Martin's minimum yearly earnings?
SELECT MIN("Earnings ( $ )") FROM table_21173
SELECT MIN("Earnings ( $ )") FROM "table_21173"