A proportionately large number of you responded to that survey.
( ( ( A ( ( proportionately large ) number ) ) ( of you ) ) ( ( responded ( to ( that survey ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (ADJP (RB proportionately) (JJ large)) (NN number)) (PP (IN of) (NP (PRP you)))) (VP (VBD responded) (PP (TO to) (NP (DT that) (NN survey)))) (. .)))
Compared to others, a large percentage of you answered that series of questions.
( ( Compared ( to others ) ) ( , ( ( ( a ( large percentage ) ) ( of you ) ) ( ( answered ( ( that series ) ( of questions ) ) ) . ) ) ) )
(ROOT (S (PP (VBN Compared) (PP (TO to) (NP (NNS others)))) (, ,) (NP (NP (DT a) (JJ large) (NN percentage)) (PP (IN of) (NP (PRP you)))) (VP (VBD answered) (NP (NP (DT that) (NN series)) (PP (IN of) (NP (NNS questions))))) (. .)))