title: Perf: what do [<n percent>] records mean in perf stat output?
body: <p><code>perf stat -e &lt;events&gt; &lt;command&gt;</code> with many different events usually returns an output like this</p>
  
  <pre><code>   127.352.815.472 r53003c                                                      [23,76%]
      65.712.112.871 r53019c                                                      [23,81%]
     178.027.463.861 r53010e                                                      [23,88%]
     162.854.142.303 r5302c2                                                      [24,05%]
     ...
  </code></pre>
  
  <p>What do the percentage records mean?</p>