Excel 2007

My horizontal axis is made up of the week number values for the year week 1
to week 53.

I have two sets of data to plot as bars against thos axis.

The first set is data from 2009 and the second set is the data collected so
far from 2010.

My problem is that the 2009 data started being collected from week 8
however, when plotted in my chart is starts from week 1.

The data range I'm selcting uses a common week row for its values with the
two sets of data (2009 & 2010) contained in rows underneath.

Any ideas?