What is the average amount of floors of the building that is ranked larger than 30, a year prior to 1977 and an address of 100 Van Ness Avenue?
CREATE TABLE table_10528 (
    "Rank" real,
    "Name" text,
    "Height ft (m)" text,
    "Floors" real,
    "Year" real
)
SELECT AVG("Floors") FROM table_10528 WHERE "Rank" > '30' AND "Year" < '1977' AND "Name" = '100 van ness avenue'
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 average amount of floors of the building that is ranked larger than 30, a year prior to 1977 and an address of 100 Van Ness Avenue? ### Input: CREATE TABLE table_10528 (
    "Rank" real,
    "Name" text,
    "Height ft (m)" text,
    "Floors" real,
    "Year" real
) ### Response: SELECT AVG("Floors") FROM table_10528 WHERE "Rank" > '30' AND "Year" < '1977' AND "Name" = '100 van ness avenue'