During what years did the tallest building, located at 211 Union Street, have less than 31 floors?
CREATE TABLE table_68776 (
    "Name" text,
    "Street Address" text,
    "Years as tallest" text,
    "Height ft / m" text,
    "Floors" real
)
SELECT "Years as tallest" FROM table_68776 WHERE "Floors" < '31' AND "Street Address" = '211 union street'
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: During what years did the tallest building, located at 211 Union Street, have less than 31 floors? ### Input: CREATE TABLE table_68776 (
    "Name" text,
    "Street Address" text,
    "Years as tallest" text,
    "Height ft / m" text,
    "Floors" real
) ### Response: SELECT "Years as tallest" FROM table_68776 WHERE "Floors" < '31' AND "Street Address" = '211 union street'