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_18118221_1 (annual_interchanges__millions__2011_12 VARCHAR, annual_entry_exit__millions__2011_12 VARCHAR)
  ### Question:
  How many annual interchanges in the millions occurred in 2011-12 when the number of annual entry/exits was 36.609 million? 
  ### Answer:
  SELECT annual_interchanges__millions__2011_12 FROM table_18118221_1 WHERE annual_entry_exit__millions__2011_12 = "36.609"