Excel 2007 : getting rid of word wrap in data table

How do I prevent the headings in a data table attached to a chart from wrapping? I created a chart and set it to display the data table. The headings are years, and right now the last digit of each year is displayed on a separate line. I attached an image of the chart. Resizing the chart and changing the font size in the data table don't work. I also tried increasing the intervals between tick marks, but that doesn't stop the wrapping, either. The default word wrap option in page layout is already turned off.