Progressive pie chart 3

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    svg { width:100%; height: 100% }
body {
    background-color: #1B1F2A;
    width: 100%;
    font-family: 'Roboto', sans-serif;
    height: 100%;
}
 
.widget {
    margin: 0 auto;
    width:350px;
    margin-top:50px;
    background-color: #3f5175;
    border-radius: 5px;
    box-shadow: 0px 0px 1px 0px #06060d;
 
}
 
.header{
    background-color: #29384D;
    height:40px;
    color:#929DAF;
    text-align: center;
    line-height: 40px;
    border-top-left-radius: 7px;
    border-top-right-radius: 7px;
    font-weight: 400;
    font-size: 1.5em;
    text-shadow: 1px 1px #06060d;
}
 
.chart-container{
    padding:25px;
}
  </style>
</head>

<body>
  
  <div class="widget">
    <div class="header">Progress Status</div>
    <div id="chart" class="chart-container">

</div>
</div>
  <script>
var percent = 65;
 
var ratio=percent/100;
 
var pie=d3.layout.pie()
        .value(function(d){return d})
        .sort(null);
 
var w=300,h=300;
 
var outerRadius=(w/2)-10;
var innerRadius=110;
 
 
var color = ['#404F70','#67BAF5','#2d384d'];
 
var arc=d3.svg.arc()
        .innerRadius(innerRadius)
        .outerRadius(outerRadius)
        .startAngle(0)
        .endAngle(2*Math.PI);
 
 
var arcLine=d3.svg.arc()
        .innerRadius(innerRadius)
        .outerRadius(outerRadius)
        .cornerRadius(20)
        .startAngle(-0.05);
 
var svg=d3.select("#chart")
        .append("svg")
        .attr({
            width:w,
            height:h,
            class:'shadow'
        }).append('g')
        .attr({
            transform:'translate('+w/2+','+h/2+')'
        });
 
var defs = svg.append("svg:defs");
 
var inset_shadow = defs.append("svg:filter")
        .attr("id", "inset-shadow");
 
inset_shadow.append("svg:feOffset")
        .attr({
            dx:0,
            dy:0
        });
 
inset_shadow.append("svg:feGaussianBlur")
        .attr({
            stdDeviation:8,
            result:'offset-blur'
        });
 
inset_shadow.append("svg:feComposite")
        .attr({
            operator:'out',
            in:'SourceGraphic',
            in2:'offset-blur',
            result:'inverse'
        });
 
inset_shadow.append("svg:feFlood")
        .attr({
            'flood-color':'black',
            'flood-opacity':1,
            result:'color'
        });
 
inset_shadow.append("svg:feComposite")
        .attr({
            operator:'in',
            in:'color',
            in2:'inverse',
            result:'shadow'
        });
 
inset_shadow.append("svg:feComposite")
        .attr({
            operator:'over',
            in:'shadow',
            in2:'SourceGraphic'
        });
 
var pathBackground=svg.append('path')
        .attr({
            d:arc
        })
        .style({
            fill:color[0],
            filter:'url(#inset-shadow)'
        });
 
 
var pathForeground=svg.append('path')
        .datum({endAngle:0})
        .attr({
            d:arcLine
        })
        .style({
            fill:color[1],
            filter:'url(#inset-shadow)'
        });
var circle=svg.append('circle')
        .attr({
            cx:0,
            cy:0,
            r:innerRadius
        })
        .style({
            fill:color[2],
            'fill-opacity':.5
        });
 
var middleCount=svg.append('text')
        .datum(0)
        .text(function(d){
            return d+'%';
        })
 
        .attr({
            class:'middleText',
            'text-anchor':'middle',
            dy:27
        })
        .style({
            fill:d3.rgb(color[1]).brighter(2),
            'font-size':'80px'
 
 
        });
 
var oldValue=0;
var arcTween=function(transition, newValue,oldValue) {
    transition.attrTween("d", function (d) {
        var interpolate = d3.interpolate(d.endAngle, ((2*Math.PI))*(newValue/100));
 
        var interpolateCount = d3.interpolate(oldValue, newValue);
        return function (t) {
            d.endAngle = interpolate(t);
            middleCount.text(Math.floor(interpolateCount(t))+'%');
            return arcLine(d);
        };
    });
};
 
 
var animate=function(){
 
    pathForeground.transition()
            .duration(750)
            .ease('cubic')
            .call(arcTween,percent,oldValue);
    oldValue=percent;
    percent=(Math.random() * 60) + 20;
    setTimeout(animate,1500);
};
 
setTimeout(animate,0);
  </script>
</body>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js