Excel 2007

I have an bar chart that has vertically oriented data labels that are
centered on each bar of the chart. I need to reproduce that for another
chart, but I'm having a hard time figuring out how I got it to work the
first time. I know how to add the series label to the chart and to flip the
labels vertically, but the labels all appear above the bar instead of being
centered within the bar. How do I get the series labels to automatically
center within each bar?

Thanks for any insight that you can provide.

--Tom