Unfortunately, this particular client was fairly new, so as a result, their Moz campaign data wasn’t around during the high organic traffic times in 2015. However, if it was, a good place to start would be looking at the search visibility metric (as long as the primary keywords have stayed the same). If this metric has changed drastically over the years, it’s a good indicator that your organic rankings have slipped quite a bit.
This is the number of views that you can test each month on your website.It's up to you how you choose to use them, either by allocating all the views to one test or to multiple test, either on one page or on multiple pages. If you have selected the 10.000 tested views plan and you run an experiment on your category page which is viewed 7000 times per month, then at the end of the month 7000 is what you'll be counted as tested views quota.