how many feet separate the 7th and 8th ranked highest peaks ?
CREATE TABLE table_203_808 (
    id number,
    "rank" number,
    "peak name" text,
    "elevation" text,
    "location" text,
    "notes" text
)
SELECT (SELECT "elevation" FROM table_203_808 WHERE "rank" = 7) - (SELECT "elevation" FROM table_203_808 WHERE "rank" = 8)
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: how many feet separate the 7th and 8th ranked highest peaks ? ### Input: CREATE TABLE table_203_808 (
    id number,
    "rank" number,
    "peak name" text,
    "elevation" text,
    "location" text,
    "notes" text
) ### Response: SELECT (SELECT "elevation" FROM table_203_808 WHERE "rank" = 7) - (SELECT "elevation" FROM table_203_808 WHERE "rank" = 8)