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_20090682_4 (vehicle VARCHAR, top_13_time VARCHAR)

### Question ###
how many vehicles where top 13 time is 1:18.72

### Accurate SQL ###

SELECT COUNT(vehicle) FROM table_20090682_4 WHERE top_13_time = "1:18.72"