I'm putting together some statistics for our Board of Trustees - begging for money to buy shelves, basically. One of the questions I'm running up against, and unable to answer, is: how much of the collection should actually be checked out at any given time? I'm talking snapshot, not turnover.
I can find this information for academic libraries, and I'm finding some really interesting chatter about crazy-high numbers at highly specialized and experimental suburban branch libraries (hey, Lone Tree!) but I can't find a realistic, typical best practice for small (under-10,000-pop, under-50,000-volume), nonspecialized, single-site public libraries.
Does anybody have a guideline for small publics? A source to point to would be GREAT, but anecdotal data is awesome too. Thanks!