Highcharts.chart('container', {

    chart: {
        type: 'areaspline'
    },

    plotOptions: {
        series: {
            stacking: 'normal',
            fillOpacity: 0.3,
            _connectNulls: true
        }
    },
    yAxis: {
        // min: -5
    },

    series: [{
        data: [1, 2, 3, 4, 5, 4, 3, 2, 1],
        pointStart: 2
    }, {
        data: [1, 2, null, 2, 1, 1]
    }, {
        data: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
    }]

});
