+--------------+----------------------+------+-----+---------+----------------+
| Field        | Type                 | Null | Key | Default | Extra          |
+--------------+----------------------+------+-----+---------+----------------+
| Index        | int(11)              | NO   | PRI | NULL    | auto_increment |
| zipcode      | varchar(6)           | NO   | MUL | NULL    |                |
| facility_nid | smallint(5) unsigned | NO   |     | NULL    |                |
| distance     | int(10) unsigned     | NO   |     | NULL    |                |
+--------------+----------------------+------+-----+---------+----------------+