Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_10007452_3 (fleet_series__quantity_ VARCHAR, fuel_propulsion VARCHAR)
### Question:
how many times is the fuel propulsion is cng?
### Answer:
SELECT COUNT(fleet_series__quantity_) FROM table_10007452_3 WHERE fuel_propulsion = "CNG"