(S (S (PP (IN At) (NP (BASENP (PRPD its) (NN peak)) (PP (IN in) (BASENP (DT the) (NNS 1970s))))) (COMMA ,) (S (BASENP (DT the) (NN program)) (VP (VBD achieved) (BASENP (QP (NN nine) (NN million)) (NNS viewers))))) (PERIOD .))