The chart type associated with the selected data series or data point determines the type of data label you can add.
To add data labels to a data series, click the data series.
To add a data label to a single data point, click the data series that contains the data marker you want to label, and then click the data marker for the data point you want to label.
On the Format menu, click Selected Data Series or Selected Data Point.
On the Data Labels tab, select the options you want — Series name, X value, Y value, Percentage (for a pie chart), Bubble size value (for a bubble chart).
Note: The options that are available will depend on the chart type you have. For example, Bubble size will only appear available for a bubble chart, otherwise it appears grayed out.
In the Separator dropdown list, select an option that you want to separate your values.
Tip: You can quickly label all data points. Click the chart, click Chart Options on the Chart menu, and then select the options you want on the Data Labels tab.