– 6 - year - old ▁children ▁who ▁are ▁reported ▁in ▁China ▁from ▁ 2 0 0 0 ▁up wards ▁was ▁ 1 0 . 3 / 1 0 , 0 0 0 . ▁ ▁Hong ▁Kong ▁A ▁ 2 0 0 8 ▁Hong ▁Kong ▁study ▁reported ▁an ▁AS D ▁inc idence ▁rate ▁similar ▁to ▁those ▁reported ▁in ▁Australia ▁and ▁North ▁America , ▁and ▁lower ▁than ▁Europe ans . ▁It ▁also ▁reported ▁a ▁pre val ence ▁of ▁ 1 . 6 8 ▁per ▁ 1 , 0 0 0 ▁for ▁children ▁under ▁ 1 5 ▁years . ▁ ▁Japan ▁A ▁ 2 0 0 5 ▁study ▁of ▁a ▁part ▁of ▁Y ok oh ama ▁with ▁a ▁stable ▁population ▁of ▁about ▁ 3 0 0 , 0 0 0 ▁reported ▁a ▁cum ulative ▁inc idence ▁to ▁age ▁ 7 ▁years ▁of ▁ 4 8 ▁cases ▁of ▁AS D ▁per ▁ 1 0 , 0 0 0 ▁children ▁in ▁ 1 9 8 9 , ▁and ▁ 8 6 ▁in ▁ 1 9 9 0 . ▁After ▁the ▁v acc ination ▁rate ▁of ▁the ▁triple ▁M MR ▁v acc ine ▁dropped ▁to ▁near ▁zero ▁and ▁was ▁replaced ▁with ▁MR ▁and ▁M ▁v acc ine , ▁the ▁inc idence ▁rate ▁grew ▁to ▁ 9 7 ▁and ▁ 1 6 1 ▁cases ▁per ▁ 1 0 , 0 0 0 ▁children ▁born ▁in ▁ 1 9 9 3 ▁and ▁ 1 9 9 4 , ▁respectively , ▁indicating ▁that ▁the ▁combined ▁M MR ▁v acc ine ▁did