title: Rails establishing frequencies of uniq values and limiting result
body: <p>With the following</p>
  
  <pre><code>@items.group(:nature_id).count(:nature_id)
  </code></pre>
  
  <p>one obtains a hash of results</p>
  
  <pre><code>{4=&gt;1, 8=&gt;1, 14=&gt;2, 27=&gt;1, 32=&gt;1, 33=&gt;1, 36=&gt;1, 41=&gt;2, 44=&gt;1, 63=&gt;1, 64=&gt;4, 69=&gt;1, 130=&gt;7, 131=&gt;3,[...]}
  </code></pre>
  
  <p>How can this result be sorted by the count value in decreasing order of said value &amp; the result limited to 100 records?</p>