title: Add up values in list
body: <p>I'm currently working with a list which contains the following data:</p>
  
  <pre><code>&gt;resultsList
  
  $`1`
  [1] "x" "0"           "1"           "1"           "1"           "5"          
  $`2`
  [1] "x /// y" "0"     "1"           "1"           "2"           "3"          
  $`3`
  [1] "x" "0"           "1"           "3"           "2"           "4"          
  $`4`
  [1] "x /// z" "0"     "1"           "2"           "2"           "2"          
  $`5`
  [1] "x" "0"           "1"           "3"           "3"           "4"          
  $`6`
  [1] "x" "0"           "0"           "0"           "1"           "2"          
  $`7`
  [1] "x" "0"           "2"           "2"           "1"           "4"               
  $`8`
  [1] "x /// y" "0"     "2"           "2"           "1"           "2"   
  </code></pre>
  
  <p>I would like to add up all the numbers per column and only keep the value in column 1 which is present in every row.</p>
  
  <p>The output should look like this:</p>
  
  <pre><code>&gt;mergedData
  
  [1] "x" "0" "9" "14" "13" "26"
  </code></pre>
  
  <p>How can I accomplish this?</p>