CREATE TABLE table_23318 ("Vehicle Category" TEXT, "Till Aligarh" FLOAT, "Till Mathura" FLOAT, "Till Agra" FLOAT, "For Round Trip" FLOAT)

How many have the Till Agra of 500?
SELECT COUNT("Till Mathura") FROM table_23318 WHERE "Till Agra" = '500'
SELECT COUNT("Till Mathura") FROM "table_23318" WHERE "Till Agra" = '500'