CREATE TABLE table_name_95 (years_as_tallest VARCHAR, floors VARCHAR, street_address VARCHAR)

During what years did the tallest building, located at 211 Union Street, have less than 31 floors?
SELECT years_as_tallest FROM table_name_95 WHERE floors < 31 AND street_address = "211 union street"
SELECT "years_as_tallest" FROM "table_name_95" WHERE "211 union street" = "street_address" AND "floors" < 31