▁traditional ▁paper ▁month ly ▁passes . ▁At ▁the ▁same ▁time , ▁many ▁more ▁commercial ▁out lets ▁permitted ▁users ▁to ▁purchase ▁and ▁re charge ▁their ▁cards . ▁While ▁some ▁commut ers ▁initially ▁compla ined ▁about ▁long ▁que ues ▁at ▁bus ▁stops , ▁the ▁system ▁has ▁now ▁been ▁adopted ▁by ▁many ▁Be ij ing ▁commut ers . ▁On ▁ 1 6 ▁May ▁ 2 0 0 6 , ▁ 4 , 4 7 1 , 8 0 0 ▁transactions ▁were ▁made ▁using ▁Y ik at ong . ▁ ▁The ▁system ▁was ▁introduced ▁on ▁some ▁tax is ▁in ▁ 2 0 0 6 , ▁and ▁all ▁Be ij ing ▁tax is ▁were ▁required ▁to ▁accept ▁Y ik at ong ▁payment ▁from ▁the ▁beginning ▁of ▁August ▁ 2 0 0 8 . ▁The ▁system ▁is ▁expected ▁to ▁be ▁further ▁expanded ▁for ▁pay ments ▁of ▁par king ▁fe es ▁and ▁express way ▁to ll s . ▁ ▁By ▁the ▁end ▁of ▁ 2 0 1 1 , ▁ 4 1 . 7 6 ▁million ▁Y ik at ong ▁cards ▁had ▁been ▁issued . ▁ ▁Cost ▁ ▁The ▁card ▁can ▁be ▁bought ▁against ▁a ▁depos it ▁of ▁C N Y ▁ 2 0 , ▁and ▁can ▁be ▁bought ▁at ▁most ▁ticket ▁coun ters ▁at ▁Be ij ing ▁Sub way ▁stations ▁and ▁some ▁bus ▁stations . ▁The ▁cards ▁can ▁be ▁re filled ▁in ▁units ▁of ▁C N Y ▁ 1 0 ▁at ▁these ▁coun ters , ▁and ▁by ▁units ▁of ▁C N Y ▁ 2 0 , ▁ 5 0