(S (S (S (BASENP (PRP It)) (VP (VP (VP (VBZ is) (RB not)) (ADJP (JJ clear))) (SBAR (WHNP (WP what)) (S (BASENP (DT these) (NNS numbers)) (VP (VBP are) (VP (VBN based) (PP (IN on)))))))) (CONJP (COMMA ,) (CC and)) (S (NP (BASENP (JJ independent) (NNS estimates)) (PP (IN of) (BASENP (DT the) (NN death) (NN toll)))) (VP (VBP are) (ADJP (RB much) (JJR higher))))) (PERIOD .))