关于echarts的柱状图如何以百分比显示的问题

option = {
    color: ['#3398DB'],
    tooltip: {
        trigger: 'axis',
        axisPointer: {            // 坐标轴指示器，坐标轴触发有效
            type: 'shadow'        // 默认为直线，可选为：'line' | 'shadow'
        },
        formatter:item=>{
            const curr = item[0].data / 280 * 100
            return parseInt(curr) + '%'
        }　
    },
    grid: {
        left: '3%',
        right: '4%',
        bottom: '3%',
        containLabel: true
    },
    xAxis: [
        {
            type: 'category',
            data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
            axisTick: {
                alignWithLabel: true
            }
        }
    ],
    yAxis: [
        {
            type: 'value',
            axisLabel: {
                min: 0,
                max:100,
                show: true,
                formatter: '{value} %'
            },
        }
    ],
    series: [
        {
            name: '直接访问',
            type: 'bar',
            barWidth: '60%',
            data: [40, 40,40, 40, 40, 40, 40],
            itemStyle: {
                 normal: {
                     label: {
                         show: true,
                         formatter:item=>{
                             const curr = item.data / 280 * 100
                             return parseInt(curr) + '%'
                         }
                     }
                 }
             },
        }
    ]
};