Hi Gordon Sir,
Yes, It is actually 16 months report. After cheking this report I realise that I actually need 16 months report, b'coz suppose you have an Open AP Invoice for the month of May 2012 and you book the outgoing payment for the same Invoice in the month of May 2013, then you need to check the report from May 2012 to May 2013 then you can be sure that you don't have any open Invoices in month of May 2012.
Regards,
Ravi