7 Day Wager Amount

[gamble260]

Has anyone figured out how to estimate the 7 day wager amount that is used for the weekly bonus and for bonus drops? 

I use the statistics email often, but often the stats email indicates a different wager amount then the bonus drop needs. Sometimes I get the bonus drop when the email indicates I haven't wagered enough, and sometimes the email says I've wagered more than enough, but the bonus drop says otherwise. 

It would be nice in the statistics popup if it would just tell us how much the 7 day wager is.