Where to customize the 's in get_highest_rated?

Hi,

I want to show the position / ranking of my posts in the ratings widget in my sidebar. (Songtester.de)

Like:
1. XXX
2. XXX
3. XXX

So where do I have to customize the “li”s in get_highest_rated? (customize to “ol”s ?)

Thanks!!!
https://wordpress.org/plugins/wp-postratings/