Stuttgart stress-free?

A small startup has just released a study about stress levels in various cities - and Stuttgart came out as the world's least stressful place:
     https://www.zipjet.co.uk/2017-stressful-cities-ranking

It is of course possible to prove whatever you want with statistics like what the study contains - but it certainly serves as a discussion starter:
What do you think about the level of stress in Stuttgart or other German cities, and how does it compare to your home country?

I would never say Stuttgart is stress free but compared to what? There always seems to be a trade off when one lives in a big city compared to a smaller one. Bigger places have more culture, more opportunities and diversity but usually more problems of crime, bad neighborhoods etc. For its size, Stuttgart has almost unbelievable cultural offerings including world class ballet, opera, museums, sports teams and facilities and many festivals. Yet there is not a neighborhood in the whole city I would have hesitation to walk through. What is behind is a mentality of keeping things orderly plus a strong and prosperous local and regional economy.