function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2018', 4],
    ['1973', 1],
    ['1959', 2],
    ['1955', 3],
    ['1948', 1],
    ['1944', 1],
    ['1943', 3],
    ['1940', 2],
    ['1937', 4],
    ['1936', 2],
    ['1933', 1],
    ['1929', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=25)',
    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);