Of possible interest to those who might like a visual overview of longer term trends and spending in the research library sector.

Kyrillidou, Martha. “[22]Research Library Trends: A Historical Picture
of Services, Resources, and Spending” [23]Research Library Issues: A
Quarterly Report from ARL, CNI, and SPARC (280)(2012): 20-27.
(http://publications.arl.org/rli280/20).

Dave Clemens