title: Calculating percentile counts in python
body: <p>I have a large array ex 
  <code>[1,4,5,9,1,4,6,....]</code></p>
  
  <p>I wanna calculate how many elements in total fall below each percentile.
  Ex: </p>
  
  <pre><code>4 numbers in 10percentile
  7 numbers in 20 percentile
  10 numbers in 30 percentile and so on till 100. ```
  
  Is there a simple way to do this
  </code></pre>