(S (S (NP (BASENP (DT A) (NN study)) (VP (VBN done) (PP (IN at) (BASENP (DT the) (NNP Christchurch) (NNP Hospital))))) (VP (VBZ has) (VP (VBN shown) (SBAR (IN that) (S (BASENP (NN 61) (NNS patients)) (VP (VBD had) (VP (VP (VBN been) (PP (TO to) (BASENP (DT the) (JJ emergency) (NN department)))) (NP (BASENP (DT a) (NN total)) (PP (IN of) (BASENP (NN 80) (NNS times))))))))))) (PERIOD .))