size

For Bubble charts, this determines the radius of the data point, relative to the other points in the series.

dataSeries: [{
    data: [
        {
            x: 161,
            y: 151,
            size: 1,
            pointName: "London"
        },
        {
            x: 170,
            y: 159,
            size: 2,
            pointName: "New York"
        },
        {
            x: 172,
            y: 155,
            size: 3,
            pointName: "Paris"
        }
    ]
}]