The top library today (in terms of queries) would have been ranked #36 back in 1995. The mean in 1995 was 210,588. While the mean in 2014 was 44,667.
The linked article is intended for librarians and academics however it inadvertently makes an important point for everyday Internet users.
You no longer need to go to a library and ask an expert to find information. Information, even obscure esoteric information, is ridiculously easy to find using the Internet and Google. In their defense (my daughter in law is a librarian) librarians do have access to more sophisticated search tools and data bases than the rest of us. Never the less data is ubiquitous, easy to find and generally free.
This has importance to dentists. People will check you out online. Patients will look at your web site, they will find user reviews, they will look for social media sites and may even check out state board and legal records before they decide to see you as a dentist.