what is the total years on the chart
CREATE TABLE table_204_620 (
    id number,
    "title" text,
    "year" number,
    "language" text,
    "role" text,
    "notes" text
)
SELECT COUNT(DISTINCT "year") FROM table_204_620
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 total years on the chart ### Input: CREATE TABLE table_204_620 (
    id number,
    "title" text,
    "year" number,
    "language" text,
    "role" text,
    "notes" text
) ### Response: SELECT COUNT(DISTINCT "year") FROM table_204_620