text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_name_60 (quantity INTEGER, year VARCHAR, model VARCHAR)
  ### Question:
  Name the sum of quantity for before 2011 model slf-230
  ### Answer:
  SELECT SUM(quantity) FROM table_name_60 WHERE year < 2011 AND model = "slf-230"