Many were looking for westerns and there was high demand for war, adventure and thriller novels.
She said librarians were encouraging those readers to move beyond their usual authors to other writers they might enjoy.
Ms Green said there was still high demand for romance novels.
Demand for paranormal horror books had dropped.
The library was targeting its buying to the areas people were using and had increased its fiction purchases and reduced its non-fiction buying.
Ms Green said the number of issues of physical books had been "extremely consistent" for the past four or five years, which was encouraging.
There was a consistent increase in the use of eBooks and audiobooks at the libraries, but the increase was not as dramatic as it had been previously.
