title: How to fix: "no applicable method for 'pull'" (dplyr)
body: <p>I have a list of several <code>NUTS2</code> codes for the years 1984-1986. I am trying to get the average GDP for each <code>NUTS2</code> region over the course of these 3 years.
  Below is the code I tried to achieve this with - unfortunately, I always retrieve an error with my last line, saying that "pull" is not an applicable method for this class.</p>
  
  <h1>The initial dataset looks as follows:</h1>
  
  <pre><code>NUTS_CODE NUTS_LEVEL SCENARIO_ID REF_YEAR IND_VALUE NUTS_C
  837      BE10          2           1     1984 2.307e+10     BE
  838      BE21          2           1     1984 2.195e+10     BE
  839      BE22          2           1     1984 6.330e+09     BE
  840      BE23          2           1     1984 1.340e+10     BE
  841      BE24          2           1     1984 9.430e+09     BE
  842      BE25          2           1     1984 1.093e+10     BE
  </code></pre>
  
  <h1>My code:</h1>
  
  <pre><code>regions &lt;- unique(as.character(gdp_nuts2_member_1984to1986$NUTS_CODE))
  data84_86 &lt;- regions
  data84_86 &lt;-cbind(data84_86, rep(as.numeric(NA), length(regions)))
  
  colnames(data84_86) &lt;- c("regions","values")
  
  
  for(i in 1:nrow(data84_86))
  {
    data84_86[i,2]&lt;-mean(pull((gdp_nuts2_member_1984to1986%&gt;%filter(NUTS_CODE == regions[i]))[,"IND_VALUE"]))
  }
  </code></pre>
  
  <blockquote>
    <p>Error in UseMethod("pull") :    no applicable method for 'pull'
    applied to an object of class "c('double', 'numeric')"</p>
  </blockquote>