title: Calculating stock per day
body: <p>In my report <a href="http://pastebin.com/HJJBCueY" rel="nofollow">http://pastebin.com/HJJBCueY</a><br>
  I would like to add another column named "Stock per day" that will store
  sum of all stock values per day . <br>
  For all rows IN 05.06.2013 that column would have value=110221, and for all rows 88777. <br>
  Thanks</p>