I have written below code for scatter chat and now I want to add group by filtering as well so I want to know how json will be form for this kind of chart which shows uptimes hours on xAxis, Downtime hours on yAxis and group by SKU. Bubble size is not important right now for me but if I can get any example with bubble size as well, it is very helpful for me scatter.jpg

HTML Code:
var chart = new Ext.chart.CartesianChart({
    animate: true,
    store: {
      fields: ['DE','DH'],
      data: [
          {'DE':10, 'DH':15},
           {'DE':15, 'DH':20},
           {'DE':20, 'DH':25},
         
      ]
    },
    axes: [{
        type: 'numeric',
        position: 'left',
        fields: ['DH'],
        title: {
            text: 'DH',
            fontSize: 15
        },
        grid: true,
        minimum: 0
    }, {
        type: 'numeric',
        position: 'bottom',
        fields: ['DE'],
        title: {
            text: 'DE',
            fontSize: 15
        },
        minimum: 0
    }],
    series: [{
        type: 'scatter',
        highlight: {
            size: 7,
            radius: 7
        },
        fill: true,
        xField: 'DE',
        yField: 'DH',
        marker: {
            type: 'circle',
            fillStyle: 'blue',
            radius: 10,
            lineWidth: 0
        }
    }]
});
Ext.Viewport.setLayout('fit');
Ext.Viewport.add(chart);
Thanks