For those of you who attempt to follow this figure on project pages at Archive, it has been changing, Their explanation is here
http://blog.archive.org/2018/12/19/new-views-stats-for-the-new-year/
It does also explain how they arrive at the figure.
I find the graphs for regions on our "collection" (that's LibriVox - we are an Archive Collection in their terminology) here https://archive.org/details/librivoxaudio&tab=about interesting.
Anne