School bullying is nowhere near universally consistent. It’s twice as common in the US as it is in the Netherlands for example and the difference between schools can be far more extreme.
Given how many people were very deeply and very personally affected by it, it's amazing that nobody's discovered how and why it spreads.
https://www.statista.com/statistics/1092217/bullying-in-euro...
https://www.pacer.org/bullying/info/stats.asp
Which suggests the rates are comparable between the US and Denmark.
Netherlands is 12% far to the right on the top link you just used, and it shows a huge range between countries.
The second link you used had 20.2% for the US.
PS: Did you think Netherlands and Denmark was the same country or something?