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_19948664_2 (index__year_ VARCHAR, world_ranking__1_ VARCHAR)
  ### Question:
  How many years were recorded when world ranking was 21st?
  ### Answer:
  SELECT COUNT(index__year_) FROM table_19948664_2 WHERE world_ranking__1_ = "21st"