       minAngle: i * interval,
                        itemStyle: {
                            borderRadius: 10,
                            borderColor: '#fff',
                            borderWidth: 2
                        },
                        data: [
                            { value: 1048, name: 'Search Engine' },
                            { value: 735, name: 'Direct' },
                            { value: 580, name: 'Email' },
                            { value: 484, name: 'Union Ads' 