No, it's statistics!
From the ATRA website:
Mathematical multi-criteria analyses have been selected by ATRA for the following reasons:
- management of both quantitative and qualitative variables
- no arbitrary weighting system
- transparency
- meaningfulness of results
- reproducibility and objectivity
Seems they can quantify their results from mathematical formula. I love the bit about reproducibility (whatever that means) and objectivity. I would say to them a quick look at how many aircraft these airlines have crashed in recent years is still an objective statistic! And they only looked at 100 airlines of which 44 had enough data to produce the survey!
The fact they've named Air France in the top ten demonstrates this report had absolutely no credibility.