Which date to use for PO spend analysis?

HI All,

I am looking for a date field to use in creating spend reports on Oracle Purchasing (R12).

Situation:

client creates po with line 1 in year 2013 - PO is approved in 2013

in 2013 another line (line 2)  is added to the PO in December and needs reapproval. The PO is approved again on January 2015.

reporting requirements:

Client wants to see all spend over 2014, using the approved date of the po line, so only line 1 will show up as spend.

Client wants to see all spend over 2015, using the approved date of the po line, so only line 2 will show up as spend.