Can any one suggest me the way of showing percentage instead of title in the C3.js donut chart ?

For any donut c3 chart is there any option to change the title value to percentage value of the selected part of the donut chart ?

I am using this code for my Donut chart.

var chart3 = c3.generate({
                bindto: '#chart3',
                data: {
                    columns: [
                        ['data1', data1],
                        ['data2', data2],
                        ['data3', data3],
                        ['data4', data4],
                        ['data5', data5],
                    ],
                    type: 'donut',
                    onclick: function (d, i) { console.log("onclick", d, i); },
                    onmouseover: function (d, i) { console.log("onmouseover", d, i); },
                    onmouseout: function (d, i) { console.log("onmouseout", d, i); }
                },
                donut: {
                    title: "Iris Petal Width"
                }
            });

and getting the following as output Donut Chart

Any Help is appreciated.