No way to tell where your iotas are from that address, it’s a very old one and you spent iotas from it already. Would help if you knew the last address where your iotas were stored before you left.
If you did not touch the iotas since the beginning of august, you missed the transition in wallet version 2.4.0. In this case, you have to click tools -> Reclaim Tool in version 2.5.4. When you’re done with this, the foundation will send the iotas to you, shoud be next week.
If you touched the iotas since august, they should still be there, they should appear when you generate as many addresses as you had before you left (it’s a display quirk of the wallet).