What is the sum number of year when Call of Duty 4: Modern Warfare was the game?
CREATE TABLE table_64966 (
    "Year" real,
    "Game" text,
    "Genre" text,
    "Platform(s)" text,
    "Developer(s)" text
)
SELECT COUNT("Year") FROM table_64966 WHERE "Game" = 'call of duty 4: modern warfare'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the sum number of year when Call of Duty 4: Modern Warfare was the game? ### Input: CREATE TABLE table_64966 (
    "Year" real,
    "Game" text,
    "Genre" text,
    "Platform(s)" text,
    "Developer(s)" text
) ### Response: SELECT COUNT("Year") FROM table_64966 WHERE "Game" = 'call of duty 4: modern warfare'