CREATE TABLE table_37237 ("Round" FLOAT, "Date" TEXT, "Grand Prix" TEXT, "Circuit" TEXT, "125cc winner" TEXT, "250cc winner" TEXT, "MotoGP winner" TEXT, "Report" TEXT)

Which Round is the lowest one that has a Circuit of donington?
SELECT MIN("Round") FROM table_37237 WHERE "Circuit" = 'donington'
SELECT MIN("Round") FROM "table_37237" WHERE "Circuit" = 'donington'