Order of navigation

Hello all,
in our navigation bar, we have some points beginning with 1, 2, 3…10.
The points are automatically sorted but in this order:
1 Title
10 Title
2 Title
3 Title

How can we change the sort order so the number 10 is after the number 9?
The code looks like:

{{velocity}}
#panelheader($services.localization.render('xe.panels.navigation'))
## Escape special characters in macro parameter values.
#set ($openToDoc = $doc.documentReference.toString().replaceAll('([~"])', '~$1'))
{{documentTree showTranslations="false" showAttachments="false" compact="true" openTo="document:$openToDoc" /}}
#panelfooter()
{{/velocity}}

Thank you for your help!

The sorting is alphanumerical. So you need to use numbers like this:

01 Title
02 Title
03 Title
10 Title