[koldtoft]

Then you have to find out.

Common solution SkinHelper (Only functional with Internet on and with a delay)
You have not made any setup on your SkinHelper AddOn.
Read Post #782 how to do that. 

Second sulution.
Use LocalInformationOnly Scraper, scrape your movies with .nfo files with a Media Manager, for example Media Companion, in the .nfo files you can get extended ratings data in it and read them into kodi.
Not recommended for laymen or people who take little time, it needs some training.

Thank you, sir. Much appreciated. 

I implemented the simple solution last night and could not get it to work, but then this morning it just worked. Maybe the API key need's some time before it starts working? I don't know. Anyway, it works now kind of. See: https://i.imgur.com/jWqWpS5.jpg
However, I don't think I can live with the delay and there is still some data missing (like the number of votes and the IMDB rating etc.) so I am going to try the second solution you suggest. 

I will let you know how it goes. Thanks again.