4 ). </ ref > ▁The ▁production ▁growth ▁was ▁almost ▁entirely ▁due ▁to ▁increased ▁product ivity ▁by ▁developing ▁nations , ▁where ▁production ▁increased ▁by ▁ 1 2 8 %. ▁ ▁During ▁that ▁same ▁time ▁period , ▁production ▁in ▁developed ▁countries ▁actually ▁decre ased . ▁China ' s ▁increase ▁in ▁to b acco ▁production ▁was ▁the ▁single ▁biggest ▁factor ▁in ▁the ▁increase ▁in ▁world ▁production . ▁China ' s ▁share ▁of ▁the ▁world ▁market ▁increased ▁from ▁ 1 7 % ▁in ▁ 1 9 7 1 ▁to ▁ 4 7 % ▁in ▁ 1 9 9 7 . ▁This ▁growth ▁can ▁be ▁partially ▁explained ▁by ▁the ▁existence ▁of ▁a ▁high ▁import ▁tar iff ▁on ▁foreign ▁to b acco ▁entering ▁China . ▁While ▁this ▁tar iff ▁has ▁been ▁reduced ▁from ▁ 6 4 % ▁in ▁ 1 9 9 9 ▁to ▁ 1 0 % ▁in ▁ 2 0 0 4 , ▁it ▁still ▁has ▁led ▁to ▁local , ▁Chinese ▁c igare tt es ▁being ▁preferred ▁over ▁foreign ▁c igare tt es ▁because ▁of ▁their ▁lower ▁cost . ▁ ▁Every ▁year ▁ 6 . 7 ▁million ▁tons ▁of ▁to b acco ▁are ▁produced ▁throughout ▁the ▁world . ▁The ▁top ▁produ cers ▁of ▁to b acco ▁are ▁China ▁( 3 9 . 6 % ), ▁India ▁( 8 . 3 % ), ▁Brazil ▁( 7 . 0 %) ▁and ▁the ▁United ▁States ▁( 4 . 6 %). ▁ ▁Major ▁produ cers ▁ ▁United ▁States ▁In ▁the ▁United ▁States , ▁as ▁of ▁ 2 0 1 4