function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2019', 1],
    ['2018', 1],
    ['2014', 2],
    ['2013', 1],
    ['2012', 31],
    ['1988', 1],
    ['1983', 3],
    ['1939', 1],
    ['1932', 1],
    ['1915', 1],
    ['1910', 1],
    ['1904', 1],
    ['1883', 1],
    ['1872', 1],
    ['1866', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=48)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerYear', 'pie', 15, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerYear'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerYear);