德國馬克
On 24 July 1984, the municipal council decided to introduce the first "environmental protection monthly ticket" despite the VAG rejecting the proposal. This system started in October 1984. At the same time, prices were reduced by up to 30 percent and the price for the transferable environmental subscriptions was set at 38 Deutsche Mark, or for concessions 32 Deutsche Mark a month (the non-transferable monthly ticket cost 51 Deutsche Mark and originally increased to 57 Deutsche Mark in 1985).