(S (S (BASENP (NNP WHO)) (VP (VBZ estimates) (SBAR (IN that) (S (NP (BASENP (NN 75) (NN %)) (PP (IN of) (BASENP (DT the) (NNS cases)))) (VP (VBP have) (VP (VBN occurred) (PP (IN in) (NP (BASENP (NNS children)) (PP (IN under) (NP (BASENP (DT the) (NN age)) (PP (IN of) (NP (BASENP (NN 5) (NNS years)) (ADJP (JJ old)))))))))))))) (PERIOD .))