Myocarditis, a risk for children who take boosters

Myocarditis is a serious risk for children, who take boosters.
Studies have shown the incidence of Myocarditis in children with one vaccine is 4/100k , for two jabs it is 25/100k, in China it is 37/100k, Ontario 36/100k.
These figures are high because there is absolutely no data to show what is the incidence of Myocarditis in children infected with myocarditis.

Another claim I find puzzling is that these toxic jabs saved 90% from ending up in hospital.
the question is how does one prove this for the current Omicron strain which has zero deaths, zero hospitalisations and zero complications.