How to add vertical bands to a combo chart (line + bar) using google developer charts

Question

I have to create a line chart, which has vertical bands in the background, and a vertical line at a specified position.Following is a sample chart image.
Sample chart

I tried to create a combo chart with line and bar as my series, to get the blue line and red vertical line. But i am unable to figure out how to get the vertical bands. Histogram is not supported by the combo chart. There is no option to create bar charts with variable width of each bar as well. Following is what i am able to create till now:
chart created so far

Following is my code:

  function drawChart() {
    // Some raw data (not necessarily accurate)
    var data = google.visualization.arrayToDataTable([
      ['Percentile', 'Number of students', 'Vertical lines',{ role: 'style' }],
      [1,  0.2020202,,''],
      [3,  0.546875,,''],
      [10,  1.20967742,,''],
      [25,  1.87969925,,''],
      [50,  1.953125, ,''],
      [75,  1.32743363,,''],
      [90,  0.64814815, ,''],
      [97,  0.25316456, ,''],
      [99,  0.00621891,,''],
      [78,  ,20,'stroke-width: 2; fill-color: red']

    ]);

    var options = {
      vAxis: {
          gridlines:{count: 6},
          viewWindow:{ max: 2.5}
         },
      hAxis: { 
        ticks: [0,20,40,60,80,100,120]
        },
      seriesType: 'line',
      series: {1: {type: 'bars'}},
      bar:{groupWidth:2},
      intervals: { 'lineWidth':2, 'barWidth': 0.5, style: 'boxes' },
      curveType: 'function',
      legend: { position: 'none' },
    };

    // Instantiate and draw our chart, passing in some options.
    var chart = new google.visualization.ComboChart(document.getElementById('curve_chart'));
    chart.draw(data, options);
  }
</script>

Please suggest how can these vertical bands be achieved?