Id like to see information on the pie chart of data older than a year.
There isn't any way to view that on TVMaze.
The only way to get information about your watched episodes would be with the Premium API
And then using the Public API - http://api.tvmaze.com/episodes/1?embed=show - to get what genre/network/etc the show is on if you want to create the graphs yourself.
Sounds like an idea for another premium feature, more extended stats on the profile page.