悬停条形图时加载旧数据-Javascript

Question

加载数据时，多大的旧数据不显示？

$.ajax({
        url : "<?= $base_url; ?>/function/ajax_function.php",
        type: "POST",
        data: {fungsi:"perhitunganPendapatan",tahun:tahun},
        success: function(hasil) {
            var dataJawaban = JSON.parse(hasil);
            bar_chart_pendapatan(dataJawaban);
        },
        error: function() {
            alert('Error !');
        }
    });

function bar_chart_pendapatan(dataJawaban="") {
    barChart.clear();
    var barChartCanvas                   = $('#barChartPendapatan').get(0).getContext('2d');
    var barChart                         = new Chart(barChartCanvas);
    var barChartData                     = dataJawaban;
    var barChartOptions                  = {
        scaleBeginAtZero        : true,
        scaleShowGridLines      : true,
        scaleGridLineColor      : 'rgba(0,0,0,.05)',
        scaleGridLineWidth      : 1,
        scaleShowHorizontalLines: true,
        scaleShowVerticalLines  : true,
        barShowStroke           : true,
        barStrokeWidth          : 2,
        barValueSpacing         : 5,
        barDatasetSpacing       : 1,
        legendTemplate          : '<ul class="<%=name.toLowerCase()%>-legend"><% for (var i=0; i<datasets.length; i++){%><li><span style="background-color:<%=datasets[i].fillColor%>"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>',
        responsive              : true,
        maintainAspectRatio     : true,
        scaleLabel              : function(valueObject){
            return valueObject.value.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ".");
        },
        tooltipTemplate: function (valueObject) {
            return "Rp. " + valueObject.value.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ".");
        }
    }

    barChartOptions.datasetFill = false;
    barChart.Bar(barChartData, barChartOptions);
}