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_29474407_11 (year_of_intro VARCHAR, name__designation VARCHAR)
### Question:
How many years of introduction does the Neal Submachine Gun have?
### Answer:
SELECT COUNT(year_of_intro) FROM table_29474407_11 WHERE name__designation = "Neal submachine gun"