Chart format

Hi,

You will find attached an Excel file:
http://cjoint.com/?lnuaOjpONZ

with 3 sheets:
- "Source"
- "Pivot table"
- "Chart"

I would like to know if it is possible to determine the same width to each
month in the graph whatever is the number bar(s) per month. (i.e., I would
like that the width allocated to "01/01/2008" with one bar "Nothing to
declare" will be same the than the width allocated to "01/03/2008" with 4
bars). And I would like that the bar(s) will be centered into the month
category in the graph as showed in the document attached:
http://cjoint.com/?lnuoEdJ4kF

Thank you in advance.