添加带有外部标签的Google图表甜甜圈

Question

我正在使用Google Chart Donut来显示标记的图例位置。它显示的是行。我想显示带有带标签的甜甜圈的百分比的文本。

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
   <script type="text/javascript">
      google.charts.load('current', {'packages':['corechart']});
      google.charts.setOnLoadCallback(drawChart);

      function drawChart() {

        var data = google.visualization.arrayToDataTable([
          ['Effort', 'Amount given'],
          ['Pacakage',     60],
          ['Single',     40]
        ]);

        var options = {
          pieHole: 0.5,
           pieSliceTextStyle: {
            color: 'white',
          },
        legend: {position: 'labeled'},

          colors: ['#046dad', 'white']
        };

        var chart = new google.visualization.PieChart(document.getElementById('donut_single'));
        chart.draw(data, options);
      }
    </script>

    <div id="donut_single" style="width: 300px; height: 300px;"></div>