PHP help needed

I’m trying to edit a theme’s sidebar to make pages hierarchical but that they stay in the order I’ve put them in.

IE. I have a parent page called 2005 and another one called 2006 with child pages inside. I want to keep those in the order they are on the manage categories page, but I want to keep the heirarchical structure.

I’m not good with code, I’ve managed to sort out my categories by using code from other themes but I can’t seem to find a theme that had pages in this way. Could someone tell me the PHP code I need to get them to display like this?

Muchos Gracias