Couples decided in COVID to go for the first kid ( or subsequent). The ones that banged for boredom still use protection... Having a kid is a choice here, not something that just happens. People have protection ;)
You're just affirming my statement.
Since the war in Ukraine ( after COVID) it dropped, it comes from insecurity.
So, those in China are insecure too, for the reason I stated.
Note : i didn't verify numbers, just explained the sentiment.