Well, the safety measures for the youngsters were implemented when the entire country was in lockdown, so, the people testing negative likely were without the virus and continuing with the lockdown other than early age schooling probably made that opening successful.

Relaxing the lockdown, especially allowing international travel and indoor dining and drinking, combined with the general disregard for danger and rules by young adults undoubtably accounts for the blooming of cases in that demographic.

Interestingly, though there has been a significant jump in cases the last month or so, there has not been the expected jump in deaths. Deaths remain at or near zero for the last 4 months.

How eager they are to be slaves - Tiberius Caesar

Coulda tripped out easy, but I've changed my ways - Donovan