What is the 1979 number for Standing Rock Indian Reservation when the 1989 is less than 54.9?
CREATE TABLE table_name_51 (
    reservation VARCHAR
)
SELECT SUM(1979) FROM table_name_51 WHERE reservation = "standing rock indian reservation" AND 1989 < 54.9
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 1979 number for Standing Rock Indian Reservation when the 1989 is less than 54.9? ### Input: CREATE TABLE table_name_51 (
    reservation VARCHAR
) ### Response: SELECT SUM(1979) FROM table_name_51 WHERE reservation = "standing rock indian reservation" AND 1989 < 54.9