Ledger Table DR/CR Amount Fields

We are upgrading to version 9.2 from version 9.1 and I am doing table compares to see what has been added or changed in GL.  In the Ledger table we have the new Dr/Cr amount fields for both Posted_Total and Posted_Tran amounts, but not for Posted_Base amount.  I am curious why even though the journals capture the Foreign and Base amounts in separate DR/CR fields why does the Ledger table not also have separate DR/CR fields like the others?

Thanks,

Kerry Redkey