title: Read the penultimate value ssrs
body: <p>i have a report with parameter is the year i can select a multiple value</p>
  
  <pre><code>            year
  Data        2010    2011   2012
   hp          14      25     30
   Dell        17      18     20
  </code></pre>
  
  <p>what i need when i create the report i want to have another column with the last value concatenation with the last previous one like this :</p>
  
  <pre><code>           year
  Data        2010    2011   2012  2012/2011
   hp          14      25     30    3025
   Dell        17      18     20    2018  
  </code></pre>
  
  <p>i tried this :</p>
  
  <pre><code>=Last(Field!Qte.value)+Last(Field!Qte.value)-1
  </code></pre>
  
  <p>but i had the wrong result i got this result :</p>
  
  <pre><code> year
  Data        2010    2011   2012  2012/2011
   hp          14      25     30    3029
   Dell        17      18     20    2019
  </code></pre>
  
  <p>the problem is in this function </p>
  
  <pre><code>Last(Field!Qte.value)-1
  </code></pre>
  
  <p>it doesn't return the last previous value </p>