function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2020', 3],
    ['2017', 2],
    ['2016', 2],
    ['2015', 9],
    ['1942', 1],
    ['1937', 2],
    ['1932', 1],
    ['1931', 1],
    ['1924', 1],
    ['1922', 1],
    ['1919', 1],
    ['1918', 1],
    ['1915', 1],
    ['1913', 2],
    ['1912', 4],
    ['Other (8)', 8]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=40)',
    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);