ElementStacks

HTML

<script src="http://highcharts.com/js/testing.js"></script>
<div id="container" style="height: 400px"></div>

JavaScript

var chart = new Highcharts.Chart({
    chart: {
        renderTo: 'container',
        zoomType: 'x'
    },
    xAxis: {
        maxZoom: 2,
        categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
    },
    plotOptions: {
        series: {
            dataLabels: {
                enabled: true,
                formatter: function(){
                    var e = this.series.xAxis.getExtremes();
                    
                    if (e.max - e.min < 6)
                        return this.y;
                        
                    return null;
                }
            }
        }
    },
    
    series: [{
        data: [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]        
    }]
});