title: What does the value of data-p means in JSSOR demos and examples?
body: <p>I've looked through all the examples and demos and browsed the documentation, but I can't find the meaning of the numerical values of data-p attribute inside of some DIV tags. I see the numbers such as 816.0, 170.0 and 112.50, but can't figure it out. What does it mean?</p>
  
  <p>Please advice.
  Thanks.</p>