Depreciatio Key for declinebalance and usefull lifr

Dear Asset experts

Please help me to configure depreciation key as per below requirement.

Tax depreciation caluclation should be decline balance method till usefull life.

system should post entire NBV as depreciation for last year.

Can some one help me how to configure depreciation to calclate depreciation as percentage

on decline balance method nad post total NBV in last year.

APC                100       

Accumilated Depreciation    36       

NBV                64       

Useful life            5 Years       

expired usefull life        2 Years       

Remaining useful life        3 Years

uploaded on            31/12/2012       

dep method decline bal        50%       

Depreciation    Depriciation    NBV   

2013    32    32   

2014    16    16   

2015    16    0    Total NBV as on 2014

Thanks

Kameshwar Rao