Did you tried to do some actions for schools? Young people have enough time for reading. I don't know about situation in your town, but this can probably help. It is cheap (it cost's you about a hour for one school) and it can rise number of readers.
Has this library internet pages? Is there a catalogue? If not, you will probably have to make it. If people have to go to the library to see the catalogue, they will not come so often (they are very lazy).