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_63 (year_joined VARCHAR, enrollment VARCHAR, ihsaa_class VARCHAR)
  ### Question:
  What year joined had an enrollment less than 438 and an AA as the IHSAA Class?
  ### Answer:
  SELECT year_joined FROM table_name_63 WHERE enrollment < 438 AND ihsaa_class = "aa"