function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2021', 4],
    ['2019', 1],
    ['2014', 1],
    ['1988', 2],
    ['1983', 1],
    ['1955', 1],
    ['1954', 1],
    ['1934', 1],
    ['1930', 1],
    ['1923', 1],
    ['1909', 1],
    ['1884', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=16)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerYear', 'pie', 12, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerYear'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerYear);