function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2021', 8],
    ['2016', 4],
    ['2014', 7],
    ['2011', 1],
    ['2004', 1],
    ['1991', 1],
    ['1988', 1],
    ['1983', 1],
    ['1980', 1],
    ['1978', 1],
    ['1974', 4],
    ['1956', 1],
    ['1939', 1],
    ['1938', 1],
    ['1924', 1],
    ['Other (2)', 2]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=36)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerYear', 'pie', 16, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerYear'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerYear);