title: Adding Row Number for Specific Field
body: <p>I have the data below in SQL. </p>
  
  <pre><code>DOB         Status       Policy StartDate   EndDate
  1/05/1983   Lapsed       P1     5/05/2015   5/06/2016
  1/05/1983   New Business P2     3/05/2016   
  2/04/1999   Lapsed       P3     5/02/2016   10/06/2017
  2/04/1999   New Business P4     10/07/2017  
  3/06/1972   Lapsed       P5     6/07/2016   15/12/2017
  3/06/1972   New Business P6     1/10/2017   
  4/12/1954   Lapsed       P7     7/03/2017   1/03/2018
  4/12/1954   New Business P8     1/03/2018   
  </code></pre>
  
  <p>I need to add descending number based on DOB field. The expected result suppose to be like below. </p>
  
  <p><a href="https://i.stack.imgur.com/1j51v.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1j51v.png" alt="enter image description here"></a></p>
  
  <p>Unfortunately I only can get number '1' in column #. </p>
  
  <p>For column #, I have tried using index(), Window_Count (Countd(DOB), 04,0), Runnning_Total (Table Down, Pane Down, Specific Dimension : DOB), however nothing works. </p>
  
  <p>I'm using Tableau desktop/server 10.0. </p>
  
  <p>Thanks all for the help. </p>