title: Finding last digits in text using stringr
body: <p>Trying to use StringR to find all the digits which occur at the end of the text. </p>
  
  <p>For example </p>
  
  <pre><code>x &lt;- c("Africa-123-Ghana-2", "Oceania-123-Sydney-200")
  </code></pre>
  
  <p>and StringR operation should return </p>
  
  <pre><code>"2  200"
  </code></pre>
  
  <p>I believe there might be multiple methods, but what would be the best code for this?</p>
  
  <p>Thanks.</p>