How to show Percentage in gauge chart of Angular google chart package?

I am developing an application where I am going to show a gauge chart. I am using the angular-google-chart package.enter image description here

I implement a basic gauge type chart. Instead of showing the flat number like 0, 100 and 78, I want to show 0%, 100% and 78% here. To do this, I am using the below coding snippet.

@ViewChild('googlechart')
  googlechart: GoogleChartComponent;
  public gaugeChart = {
    type: 'Gauge',
    data: [
      ['Water', 35]
    ],
    options: {
      width: 500,
      height: 500,
      greenFrom: 50,
      greenTo: 100,
      redFrom: 0,
      redTo: 20,
      yellowFrom: 20,
      yellowTo: 50,
      minorTicks: 5
    }
  };

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