▁tr end ▁analysis ▁found ▁no ▁correlation ▁between ▁pre val ence ▁of ▁M MR ▁v acc ination ▁and ▁the ▁inc idence ▁of ▁aut ism ▁in ▁each ▁birth ▁coh ort ▁from ▁ 1 9 8 8 ▁to ▁ 1 9 9 3 ." ▁ ▁United ▁States ▁CD C ' s ▁most ▁recent ▁estimate ▁is ▁that ▁ 1 ▁out ▁of ▁every ▁ 5 9 ▁children , ▁or ▁ 1 6 . 8 ▁per ▁ 1 , 0 0 0 , ▁have ▁some ▁form ▁of ▁AS D ▁as ▁of ▁ 2 0 1 4 . ▁The ▁number ▁of ▁diagn osed ▁cases ▁of ▁aut ism ▁grew ▁dram atically ▁in ▁the ▁U . S . ▁in ▁the ▁ 1 9 9 0 s ▁and ▁early ▁ 2 0 0 0 s . ▁For ▁the ▁ 2 0 0 6 ▁surve ill ance ▁year , ▁identified ▁AS D ▁cases ▁were ▁an ▁estimated ▁ 9 . 0 ▁per ▁ 1 0 0 0 ▁children ▁aged ▁ 8 ▁years ▁( 9 5 % ▁confidence ▁interval ▁[ CI ] ▁= ▁ 8 . 6 – 9 . 3 ). ▁These ▁numbers ▁measure ▁what ▁is ▁sometimes ▁called ▁" admin istr ative ▁pre val ence ", ▁that ▁is , ▁the ▁number ▁of ▁known ▁cases ▁per ▁unit ▁of ▁population , ▁as ▁opposed ▁to ▁the ▁true ▁number ▁of ▁cases . ▁This ▁pre val ence ▁estimate ▁rose ▁ 5 7 % ▁( 9 5 % ▁CI ▁ 2 7 % – 9 5 %) ▁from ▁ 2 0 0 2 ▁to ▁ 2 0 0 6 . ▁