CHICAGO--(BUSINESS WIRE)--Fitch Ratings has affirmed Palm Beach County, Florida's $85.9 million of outstanding airport system revenue bonds at 'A'. The bonds were issued on behalf of the Palm Beach International Airport. The Rating Outlook is Stable. The airport's rating reflects a moderately stable traffic base that serves an affluent area of South Florida with a balance of year-round business and leisure travel, but is still exposed to some economic cyclicality. The airport's carrier mix is d