[Michlib-l] Public Libraries: How often should you change auditors?

Hello All, I am interested in learning if there are any official recommendations about how often a public library should change it's auditor. We have used the same auditor for the past seven audits of our financial records. We are quite satisfied with this firm, but we do not want to grow to comfortable or cozy. Are there any standards about this that might be helpful to us? Thanks for any assistance with this issue. Frederick J. Kirby, Library Director Benton Harbor Public Library 213 East Wall St. Benton Harbor, MI 49022 269-926-6139 (voice) 269-926-1674 (fax) libraryfjk@yahoo.com