CREATE TABLE table_13607 ("Year" FLOAT, "Finish position" TEXT, "1st day" TEXT, "2nd day" TEXT, "3rd day" TEXT, "4th Day" TEXT)

How many years have a 4th Day of bumped wolfson?
SELECT COUNT("Year") FROM table_13607 WHERE "4th Day" = 'bumped wolfson'
SELECT COUNT("Year") FROM "table_13607" WHERE "4th Day" = 'bumped wolfson'