Chartjs-Chart.js add label inside bubble chart

To achieve expected result, use below option

HTML:

<section class="content" ng-app="myApp" ng-controller="ChartCtrl">
  <canvas chart-data="data" chart-labels="labels" chart-options="options" chart-series="series" class="chart-bubble" id="base"></canvas>
</section>
<span  id="q1">Quadrant1</span>
<span  id="q2">Quadrant2</span>
<span  id="q3">Quadrant3</span>
<span  id="q4">Quadrant4</span>

CSS:

#q1{
  position:absolute;
  margin-top:-30%;
  margin-left:80%;
}
#q2 {
  position: absolute;
  margin-top: -30%;
  margin-left: 20%;
}
#q3 {
  position: absolute;
  margin-bottom: -30%;
  margin-left: 20%;
}
#q4 {
  position: absolute;
  margin-bottom: -30%;
  margin-left: 80%;
}

Codepen- http://codepen.io/nagasai/pen/LkmZkL