title: Group rows in maximum 2 rows per group
body: <p>I have a dataset like the following
  <a href="http://sqlfiddle.com/#!18/149382/2" rel="nofollow noreferrer">http://sqlfiddle.com/#!18/149382/2</a></p>
  
  <p>And the result should be like the following</p>
  
  <pre><code>TripGroup  Grouper1      Grouper2      Date         Hour              Code    Description
  1          6EA579BEA901  58639247D5CB  2018-02-03   00:01:00.0000000  3962X1  GARAG EXTRA
  1          6EA579BEA901  58639247D5CB  2018-02-03   00:03:00.0000000  3962X2  RET  EXTRA/GARAG
  2          6EA579BEA901  58639247D5CB  2018-02-03   05:45:00.0000000  3962X1  GARAG EXTRA
  2          6EA579BEA901  58639247D5CB  2018-02-03   07:30:00.0000000  3962X2  RET  EXTRA/GARAG
  3          6EA579BEA901  58639247D5CB  2018-02-03   05:55:00.0000000  3962X1  GARAG EXTRA
  3          6EA579BEA901  58639247D5CB  2018-02-03   07:30:00.0000000  3962X2  RET  EXTRA/GARAG
  4          6EA579BEA901  58639247D5CB  2018-02-03   14:45:00.0000000  3962X1  GARAG EXTRA
  4          6EA579BEA901  58639247D5CB  2018-02-03   15:40:00.0000000  3962X2  RET  EXTRA/GARAG
  </code></pre>
  
  <p>My problem is when 2 GARAG start before the RET</p>
  
  <p>All groups should have one line starting with GARAG and one with RET</p>