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_55 (year VARCHAR, game VARCHAR)
### Question:
What is the sum number of year when Call of Duty 4: Modern Warfare was the game?
### Answer:
SELECT COUNT(year) FROM table_name_55 WHERE game = "call of duty 4: modern warfare"