EPPlus: Customizing clustered bar chart data label text - epplus

Question

I have created a clustered bar chart with EPPlus as shown here:
I would like to customize each bar label to include the percentage, as pictured here:
How can I customize the label? I didn't see any ability to do this via the DataLabel.
Here is the code used to create the data and chart:
var startCell = worksheet.Cells[1, 1];
startCell.Offset(0, 0).Value = "Theme";
startCell.Offset(0, 1).Value = "Count";
startCell.Offset(0, 2).Value = "%";
startCell.Offset(1, 0).Value = "Working Remotely";
startCell.Offset(1, 1).Value = 53;
startCell.Offset(1, 2).Value = 0.11;
startCell.Offset(2, 0).Value = "Collaboration";
startCell.Offset(2, 1).Value = 42;
startCell.Offset(2, 2).Value = 0.05;
worksheet.Cells[FromRow: 2, FromCol: 3, ToRow: 3, ToCol: 3].Style.Numberformat.Format = "0%";
worksheet.Cells[FromRow: 1, FromCol: 1, ToRow: 3, ToCol: 3].AutoFitColumns();
var barChart = (ExcelBarChart) worksheet.Drawings.AddChart("ThemeBarChart", eChartType.BarClustered);
barChart.SetPosition(4, 0, 0, 0);
barChart.SetSize(500, 150);
barChart.Series.Add(worksheet.Cells[FromRow: 2, FromCol: 2, ToRow: 3, ToCol: 2], worksheet.Cells[FromRow: 2, FromCol: 1, ToRow: 3, ToCol: 1]);
barChart.Legend.Remove();
var xAxis = barChart.XAxis;
xAxis.MajorTickMark = eAxisTickMark.None;
xAxis.MinorTickMark = eAxisTickMark.None;
xAxis.Fill.Style = eFillStyle.NoFill;
var yAxis = barChart.YAxis;
yAxis.Deleted = true;
yAxis.RemoveGridlines();
var dataLabel = barChart.Series[0].DataLabel;
dataLabel.Position = eLabelPosition.OutEnd;
dataLabel.ShowValue = true;