What set-up is needed to have depreciation end the date it started + the number of years instead of

This is the situation I am facing. Our assets are depreciated in a linear way for four years (48 months), depreciation stars on the actual depreciation start date.  Assets with a depreciation start date in januari 2007 all end now in december 2010. Is this standard behaviour or can I influence this in my depreciation definition?

My current definition is:

Depreciation Method: 01 -  Initial Term apportionment: A - Compute Direction: C - Life (Periods): 48  

Conventions: blank