This means a TFR of 0.91. Assuming it stays this way, what can be estimates of when the Chinese threat will be over? Like, time when prime age manpower (18-27)

This means a TFR of 0.91. Assuming it stays this way, what can be estimates of when the Chinese threat will be over? Like, time when prime age manpower (18-27) in China will be below U.S.?