I found this donut chart animation and was wondering how to trigger the animation on scroll?
$(document).ready(function() {
  $('#circle-1').circliful();
  $('#circle-2').circliful();
  $('#circle-3').circliful();
});body {
  font-family: helvetica;
  font-weight: 100;
  background: white;
  text-align: center;
  padding: 1em;
}
.circle {
  margin: 0 auto;
  display: inline-block;
  margin-right: 1em;
}<link href="//rawgit.com/pguso/jquery-plugin-circliful/master/css/jquery.circliful.css" rel="stylesheet"/>
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="//rawgit.com/pguso/jquery-plugin-circliful/master/js/jquery.circliful.js"></script>
<div id="circle-1" class="circle" data-dimension="150" data-text="85%" data-info="Sweet" data-width="15" data-fontsize="24" data-percent="85" data-fgcolor="#61a9dc" data-bgcolor="#eee" data-fill="#ddd" data-total="100" data-part="85"></div>
<div id="circle-2" class="circle" data-dimension="150" data-text="30%" data-info="Terrible" data-width="15" data-fontsize="24" data-percent="30" data-fgcolor="#61a9dc" data-bgcolor="#eee" data-fill="#ddd" data-total="100" data-part="30"></div>
<div id="circle-3" class="circle" data-dimension="150" data-text="100%" data-info="Drunk" data-width="15" data-fontsize="24" data-percent="100" data-fgcolor="#61a9dc" data-bgcolor="#eee" data-fill="#ddd" data-total="100" data-part="100"></div> 
     
    