Pie chart looking like a Gauge

Making a pie chart look like a donut/gauge - label at center.

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/require.js/2.1.19/require.min.js"></script>
<script src="//webdetails.github.io/ccc/charts/lib/amd/require.config.js"></script>
<script src="//webdetails.github.io/ccc/charts/lib/q01-01.js"></script>
<div id="cccExample" />

JavaScript

require([
  "ccc/pvc", 
  "ccc/def", 
  "ccc/protovis"
], function(pvc, def, pv) {

    new pvc.PieChart({
        canvas: 'cccExample',
        width:  300,
        height: 300,

        animate:    false,
        selectable: true,
        hoverable:  true,

        valuesVisible: true,
        valuesLabelStyle: 'inside',
        valuesFont: '35px sans-serif',
        valuesMask: '{value.percent}',

        label_visible: function() { return !this.index; },
        label_left: null,
        label_top: null,
        label_textAngle: 0,
        label_textAlign: 'center',
        label_textBaseline: 'middle',
        label_strokeStyle: 'black',

        slice_innerRadiusEx: '85%',

        categoryRole: "series",

        slice_fillStyle: function() {
          return this.index === 0 ? this.delegate() : "lightgray";
        }
    })
    .setData(relational_04b, {crosstabMode: false})
    .render();
});