I have an issue regarding X label positioning on bar chart.
Here is what I get now : http://imageshack.us/photo/my-images/199/avantj.png/
And here is what I would like to get : http://imageshack.us/photo/my-images/41/aprsr.png/
With more detailed explanations, on the first image, the mark corresponding to the X label is placed right under the middle of the bar. I would like this mark to be placed at the beginning of the bar, and thus the next mark to placed at the beginning of the following bar. The corresponding label should stay under the mark and not between those two marks.
Thank you in advance for your help.