CREATE TABLE table_45416 ("Race Title" CLOB, "Circuit" CLOB, "City / State" CLOB, "Date" CLOB, "Winner" CLOB, "Team" CLOB)

what is the circuit when the date is 16 april?
SELECT "Circuit" FROM table_45416 WHERE "Date" = '16 april'
SELECT "Circuit" FROM "table_45416" WHERE "Date" = '16 april'