MACRS STL MM - Half month Depreciation using 24 prorate periods

Hi Gurus,

I am trying to setup MACRS STL MM depreciation method using 24 prorate periods so that only half month depreciation is calculated for the first and last month of the assets life. I have setup table based rates for 24 periods, a 24 period prorate calendar and a mid-month convention that maps the appropriate calendar dates to the middle of the month. I find that the annual depreciation calculation for the asset is correct, but the depreciation amount total for the first year is divided evenly for all the periods in the 'first' year of asset's life. How do I