I believe those aileron up and down figures are teh maximum recommended travel for the surfaces for normal flying.  Having more up than down is called aileron differental and it is intended to reduce adverse Yaw when using the ailerons.

The down aileron will lift the wing but also creates drag on that side so it pulls the wing away from the intended turn, creating adverse yaw.  This is true for all aircraft but is more pronounced on gliders due to their long wings and lower flying speeds without power.