title: Find the number of times a certain value appears in previous rows
body: <p>I have something like this and want the number of transcation done by USER1 up until that moment:</p>
  
  <pre>
  USER1 - 12$
  USER2 -  9$
  USER1 -  8$
  USER3 - 18$
  USER1 - 34$
  </pre>
  
  <p>and I need something like this please:</p>
  
  <pre>
  USER1 - 12$ - 1
  USER2 -  9$ - 1
  USER1 -  8$ - 2
  USER3 - 18$ - 2
  USER1 - 34$ - 3
  </pre>
  
  <p>The last column shows the number of total transactions by the user 1.</p>