Stick with whatever you like, but for the record...
*I did calculate my spend at PIA. As most of the $ amount was loaded to the last few months, the voucher amount is unsurprisingly correct.
*I wrote to PIA Sales Support and asked for clarification of the wording "in the last year". I quote the response, with permission -
"Thanks for contacting support.
Our system calculates voucher based upon the 12 months previous spend. So for example, in calculating July 2018 vouchers the system takes into account the purchases made June 2017-June 2018. The system does often require 1-2 months to move members in and out of voucher tiers.
Let us know if you have any additional questions.
Best,
Sade
The Plugin Alliance Support Team"
I suggest that you check your spend dates for June 2017 - June 2018 and see if you're still at the level you expected to be. If you're not getting that to which you're entitled per above, I suggest you contact PIA Sales Support.
This information may be helpful in creating a PIA spending strategy. If one is in love with the increased voucher amounts, it's advisable to load up some expenditures toward the end of the trailing 12 month period.
I did not explicitly ask the question, but as PIA publishes the spend amounts which qualify for each voucher category via monthly emails, it argues against their "adjusting" the voucher qualifications randomly or in conjunction with other marketing tactics without prior announcement. However IANAL.
You're welcome, Jack and you can probably leverage the information with the CFO.