function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2019', 7],
    ['2017', 1],
    ['2012', 1],
    ['2011', 1],
    ['2007', 1],
    ['1989', 1],
    ['1975', 1],
    ['1974', 3],
    ['1973', 2],
    ['1963', 1],
    ['1951', 1],
    ['1922', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=21)',
    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);