What is the length (miles) when pico to 7th st/metro center are the endpoints?
CREATE TABLE table_72971 (
    "Segment description" text,
    "Date opened" text,
    "Line(s)" text,
    "Endpoints" text,
    "# of new stations" text,
    "Length (miles)" text
)
SELECT "Length (miles)" FROM table_72971 WHERE "Endpoints" = 'Pico to 7th St/Metro Center'
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 length (miles) when pico to 7th st/metro center are the endpoints? ### Input: CREATE TABLE table_72971 (
    "Segment description" text,
    "Date opened" text,
    "Line(s)" text,
    "Endpoints" text,
    "# of new stations" text,
    "Length (miles)" text
) ### Response: SELECT "Length (miles)" FROM table_72971 WHERE "Endpoints" = 'Pico to 7th St/Metro Center'