for how many years was the encyclopedia printed ?
CREATE TABLE table_204_843 (
    id number,
    "volume" number,
    "year" text,
    "names" text,
    "articles" number,
    "pages" number,
    "images" number,
    "maps" number,
    "number of copies" number
)
SELECT COUNT("year") FROM table_204_843
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: for how many years was the encyclopedia printed ? ### Input: CREATE TABLE table_204_843 (
    id number,
    "volume" number,
    "year" text,
    "names" text,
    "articles" number,
    "pages" number,
    "images" number,
    "maps" number,
    "number of copies" number
) ### Response: SELECT COUNT("year") FROM table_204_843