title: how to track a single download speed with asihttprequest
body: <p>Can someone help me with asihttprequest ?</p>
  
  <p>I want to track the speed download of each file I download and not the average speed of all the files.</p>
  
  <p>For the average spped of all downloads, there is <code>[ASIHTTPRequest averageBandwidthUsedPerSecond]</code>
  but what can I use to track each downloads?</p>
  
  <p>Thanks </p>