Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_23318 ( "Vehicle Category" text, "Till Aligarh" real, "Till Mathura" real, "Till Agra" real, "For Round Trip" real )

### Question ###
How many have the Till Agra of 500?

### Accurate SQL ###

SELECT COUNT("Till Mathura") FROM table_23318 WHERE "Till Agra" = '500'