Postal Service could increase those same rates by at least 13.
( ( Postal Service ) ( ( could ( ( increase ( those ( same rates ) ) ) ( by ( ( at least ) 13 ) ) ) ) . ) )
(ROOT (S (NP (NNP Postal) (NNP Service)) (VP (MD could) (VP (VB increase) (NP (DT those) (JJ same) (NNS rates)) (PP (IN by) (NP (QP (IN at) (JJS least) (CD 13)))))) (. .)))
The rates could go up by 13 during a Postal Service increase.
( ( The rates ) ( ( could ( ( ( go up ) ( by 13 ) ) ( during ( a ( Postal ( Service increase ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS rates)) (VP (MD could) (VP (VB go) (PRT (RP up)) (PP (IN by) (NP (CD 13))) (PP (IN during) (NP (DT a) (NNP Postal) (NNP Service) (NN increase))))) (. .)))