Tax rate or Rounding value

Hi all!

I am looking for a way to determine the tax rate from an invoice.

I use the BAPI BAPI_INCOMINGINVOICE_GETDETAIL.

The structure TAXDATA return only the tax code (eg: V9) and the amount but not the rate.

I know that I can use the table T007V to determine the tax rate (T007V-KBETR) associated to the tax code but how to find the table key of this table?

An other way could be to calculate the tax rate but by using this way I could find 19.60119 or 19.5911.

Do you know a way to round the value to 19.60 wich is the tax rate of the tax code V9 (eg)?

I must find the simpliest way for this because the program is not optimize and i do not want to have time out.

David