如何在Epplus饼图中显示带小数的百分比？

using OfficeOpenXml;
using OfficeOpenXml.Drawing.Chart;

// 创建ExcelPackage对象
using (var package = new ExcelPackage())
{
    // 创建工作表
    var worksheet = package.Workbook.Worksheets.Add("饼图");

    // 添加数据
    worksheet.Cells["A1"].Value = "标签";
    worksheet.Cells["B1"].Value = "数值";
    worksheet.Cells["A2"].Value = "标签1";
    worksheet.Cells["B2"].Value = 0.25;
    worksheet.Cells["A3"].Value = "标签2";
    worksheet.Cells["B3"].Value = 0.35;
    worksheet.Cells["A4"].Value = "标签3";
    worksheet.Cells["B4"].Value = 0.4;

    // 创建饼图对象
    var chart = worksheet.Drawings.AddChart("饼图", eChartType.Pie3D) as ExcelPieChart;

    // 设置饼图的位置和大小
    chart.SetPosition(0, 0, 0, 0);
    chart.SetSize(400, 400);

    // 设置饼图的数据源
    var series = chart.Series.Add(worksheet.Cells["B2:B4"], worksheet.Cells["A2:A4"]);

    // 设置饼图的显示样式
    series.Style.Fill.PatternType = OfficeOpenXml.Drawing.ExcelFillStyle.Solid;
    series.Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.Blue);
    series.Style.Border.BorderAround(OfficeOpenXml.Drawing.ExcelBorderStyle.Thin);

    // 设置饼图的数据标签
    series.DataLabel.ShowPercent = true;
    series.DataLabel.ShowValue = true;
    series.DataLabel.ShowLeaderLines = true;
    series.DataLabel.Separator = " ";
    series.DataLabel.TextFormat = "0.00%";

    // 将饼图添加到工作表中
    chart.SetPosition(1, 0, 4, 0);

    // 保存Excel文件
    package.SaveAs(new FileInfo("饼图.xlsx"));
}