function drawChartTreatmentsPerYear() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['2020', 2],
    ['1983', 1],
    ['1978', 1],
    ['1977', 1],
    ['1971', 1],
    ['1968', 1],
    ['1966', 1],
    ['1963', 1],
    ['1959', 1],
    ['1957', 1],
    ['1956', 1],
    ['1955', 7],
    ['1953', 1],
    ['1952', 1],
    ['1920', 1],
    ['Other (5)', 5]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Year (n=27)',
    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);