Hi Dan ,
I have understood your requirement a little differently ; I assume you have a range , let us say one column , of text cells , and another column of percentage values.
You have plotted the column of percentage values , and have displayed the data labels , which are obviously the percentage values.
Now , you wish to display the values only where the associated column of text cells has text in them , and do not wish to display data labels against those percentage values which have no text in the associated cell.
On the lines of what Montrey has posted , set up a helper column , say in column C , where you have the formula :
=IF(A2<>"",A2&" - "&B2*100&" %","")
copied down.
Column A contains either blank cells or cells with text data in them ; column B contains the percentage values.
After the data labels are displayed , click on each one in turn , and in the formula bar , select the respective cell from column C.
Narayan