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_name_31 (year VARCHAR, engine VARCHAR)
### Question:
Which year has has a Engine of maserati straight-6?
### Answer:
SELECT COUNT(year) FROM table_name_31 WHERE engine = "maserati straight-6"