How can we track Gmail spam compliance with Google Postmaster Tools?

[Nowell]

This is in the announcement for the new Yahoo and Gmail requirements:

1. Keep a complaint rate of < 0.3% and ideally below 0.1% to prevent mail from getting filtered into customers’ spam folders. Complaint rates are calculated as the number of emails customers are marking as spam / the number of emails that are getting inboxed. Check your Gmail complaint rate by setting up Google Postmaster Tools 

This is vague. Google Postmaster tools doesn't show an average. It shows a graph with a blue line that goes up and down, so how do we know if we are in compliance by using it?  Over what period of time do we have to maintain this SPAM rate? Is it an average over the last week, 30 days, forever? That is a key piece of information left out of the announcement.

[DylanNadeau26]

Has anyone found an answer yet?