There are two different ways to access your publication level statistics:
A. You can view the statistics of a particular publication through the Publication List.
In the top right menu go to PUBLISH, select Publisher Dashboard and go to PUBLICATION LIST.
Locate the publication whose statistics you want to view and click on STATISTICS.
From here you will be able to view the publication statistics.
B. If you are on a Premium or Optimum plan, you can access the publication level statistics also through Account Level Statistics.
Under Account Level Statistics, locate All Publications in the middle of the page. By clicking on a particular publication you will be able to see its statistics.