I think this context is important, thank you for providing it. If i were to summarize succinctly I would say the lifetime of a book in a library is akin to the

I think this context is important, thank you for providing it. If i were to summarize succinctly I would say the lifetime of a book in a library is akin to the lifetime of a car at a rental car company. The natural wear and tear on it is far greater than one that is owned by a single, private owner, and so the expected lifetime becomes much shorter.