Google Charts: Data label with suffix - charts

Question

I am just starting with using google charts. I have a question. I would like to add data labels to my columns, in fact I have succeeded in this. However, I would like to add a suffix to these labels (percentages %). I have tried to use NumberFormat, but then no chart appears. What am I doing wrong?
<script type="text/javascript" src="https://www.google.com/jsapi"></script><script type="text/javascript">
google.load('visualization', '1', { 'packages': ['corechart'] } );
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Kenmerk', 'Belangrijkheid', { role: 'style' } ],
['Uitstellen', 10, 'color: gray'],
['bijwerkingen', 20, 'color: yellow'],
['behandelingen', 30, 'color: red'],
['Schema', 40, 'color: blue']
]);
var view = new google.visualization.DataView(data);
view.setColumns([0, 1,
{ calc: "stringify",
sourceColumn: 1,
type: "string",
role: "annotation" },
2]);
// Set chart options
var options = {
width: 800,
height: 600,
title: 'Uitslag',
vAxis: { title: 'belangrijkheid van elk kenmerk in percentages uitgedrukt', format: '#\'%\'', maxValue: '100', minValue: '0'},
legend: { position: 'none'},
bar: { groupWidth: '75%' },
};
// Instantiate and draw our chart, passing in some options.
var chart = new google.visualization.ColumnChart(document.getElementById("columnchart_values"));
chart.draw(view, options);
}
</script></p>
<div id="columnchart_values" style="width: 800px; height: 600px;">
</div>