Ruben:
Thanks for your question about translations in wikistats ( http://stats.wikimedia.org). You can contribute translations to wikistats via translate wiki.
https://translatewiki.net/wiki/Translating:Wikistats_2.0
I think on our end we need to do a bit better at making obvious this is the case so we shall add a test to translate wiki to the footer of wikistats.[1]
Thanks,
Nuria