Similarly I'm 8 for 10 and have been working for nearly 20 years. So I get a score of 80.
If I had an 80% success rate, but was 18 for 20 I'd score 117. To get that, I'd need to be changing jobs every single year.
The score is not only totally made up but pointless and adds nothing to the rest of the article. It's just there to suck you into the article.