CREATE TABLE table_1203 ("No" FLOAT, "Date" TEXT, "Round" TEXT, "Circuit" TEXT, "Pole Position" TEXT, "Fastest Lap" TEXT, "Race Winner" TEXT, "Report" TEXT)

Which round was the circuit Assen
SELECT "Round" FROM table_1203 WHERE "Circuit" = 'Assen'
SELECT "Round" FROM "table_1203" WHERE "Circuit" = 'Assen'