function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2021', 2],
    ['2016', 4],
    ['2015', 4],
    ['2013', 4],
    ['2012', 2],
    ['2010', 3],
    ['2009', 10],
    ['2007', 5],
    ['2005', 3],
    ['2003', 1],
    ['1999', 9],
    ['1964', 5],
    ['1941', 1],
    ['1929', 1],
    ['1797', 1],
    ['Other (1)', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=56)',
    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);