CREATE TABLE table_16639 ("Rd." FLOAT, "Grand Prix" TEXT, "Pole Position" TEXT, "Fastest Lap" TEXT, "Winning Driver" TEXT, "Constructor" TEXT, "Report" TEXT)

What number is the Canadian Grand Prix on the list?
SELECT "Rd." FROM table_16639 WHERE "Grand Prix" = 'Canadian Grand Prix'
SELECT "Rd." FROM "table_16639" WHERE "Grand Prix" = 'Canadian Grand Prix'