CREATE TABLE table_16287 ("Rnd" CLOB, "Race Name" CLOB, "Circuit" CLOB, "City/Location" CLOB, "Date" CLOB, "Pole position" CLOB, "Fastest lap" CLOB, "Winning driver" CLOB, "Winning team" CLOB, "Report" CLOB)

On how many dates did the Michigan International Speedway hold a round?
SELECT COUNT("Date") FROM table_16287 WHERE "Circuit" = 'Michigan International Speedway'
SELECT COUNT("Date") FROM "table_16287" WHERE "Circuit" = 'Michigan International Speedway'