title: Rownumber() function of RDLC report isn't correct
body: <p>Below figure is my report. 
  This tablix has 10 row from dataset.</p>
  
  <p>It's grouped by TOOL_CODE and TYPE for get count.
  At "Count" Column is use this expression ..</p>
  
  <pre><code>   = Count("Detials")  
  </code></pre>
  
  <p>"Detials"  is a name of group(by TOOL and TYPE)</p>
  
  <p>And No.Column I use expression by Rownumber() function like these</p>
  
  <pre><code>   = Rownumber(Nothing)
  </code></pre>
  
  <p>It's wrong because Rownumber() refer to items in dataset. 
  It's not count from row which is display.</p>
  
  <p><a href="https://i.stack.imgur.com/5zd4P.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5zd4P.png" alt="enter image description here"></a></p>