title: Average number of rows created per day?
body: <p>Example table structure:</p>
  
  <pre><code>+-------------------------+---------------+------+-----+-----------------------+-----------------------------+
  | Field                   | Type          | Null | Key | Default               | Extra                       |
  +-------------------------+---------------+------+-----+-----------------------+-----------------------------+
  | id                      | char(25)      | NO   | PRI | NULL                  |                             |
  | created_at              | timestamp     | NO   |     | CURRENT_TIMESTAMP     | on update CURRENT_TIMESTAMP |
  +-------------------------+---------------+------+-----+-----------------------+-----------------------------+
  </code></pre>
  
  <p><em>How do I find out the average number of rows added per day?</em></p>