title: NSURL Loading data percentage Value
body: <p>I need to read NSURL Loading data percentage value.</p>
  
  <p>That is, I want to read how many percentage amount of data is loading on URL Loading time.</p>
  
  <p>Suppose a URL take 30 seconds to loading data completely, I want to know in 15th sec how many  percentage of data is loading in my String, and 20th sec how many percentage of data is loading in my String, like this I need. </p>