Highchart:工具提示的Json数组

我有一个Json数组如下:

[{"label":"08'/09'/2015 03:15:49 AM","y":0.6,"y1":0.3,"y2":"0.3(XYZ)","y3":"0.6(XYZ)"},
 {"label":"03'/09'/2015 04:23:04 AM","y":0.2,"y1":0.4,"y2":0.4,"y3":0.2},
 {"label":"02'/09'/2015 12:50:56 AM","y":0.4,"y1":0.4,"y2(XYZ)":0.4,"y3":0.4}]

和我的javascript代码HighChart如下:

    for (var i = 0; i < length; i++) {
        dataXAxis.push(obj[i].label);
        dataPointsLeft.push(obj[i].y);
        dataPointsRight.push(obj[i].y1);
        dataPointsLeft1.push(obj[i].y2);
        dataPointsRight1.push(obj[i].y3);
    }
     $('#xyz').highcharts({
            title: {
                text: "Demo",
                x: -20 //center
            },
            xAxis: {
                categories: dataXAxis
            },
            tooltip: {
                useHTML: true,
                shared: true
            },
            series: [{
                    name: "X",
                    data: dataPointsRight,
                    color: '#FF0000'
                }, {
                    name: "Y",
                    data: dataPointsLeft,
                    color: '#0000FF'
                }]
        });

现在我的问题是，我想在工具提示中显示"dataPointsLeft1"数组。现在我的工具提示显示与dataPointsLeft数据相同，但我想从"dataPointsLeft1"数组的工具提示上的数据。请尽快告知。

谢谢。