Probably wrong maintenance cost for ferries in 100.0

[robofish]

I'm not sure this is a bug, but the air cushion ferry can't run profitable with maintenance of 125.00c/km.
I think this got mixed up with the maintenance of the steamer (10.50c/km for 800 passengers; air cushion ferry: 125.00c/km for 278 passengers).

[prissi]

I depends strongly on the year. It should be able to run with oprofit, of always 70% filled. But currently I will check the income anyway, since there are many more unbalanced engines and so on.