In Medicare beneficiaries, the average cumulative annual incidence of any type of pneumonia was 47.4 per 1,000 from 2005 to 2007.
Thomas, Cindy P., Marian Ryan, John D. Chapman, William B. Stason, Christopher P. Tompkins, et al. Incidence and Cost of Pneumonia in Medicare Beneficiaries. Chest. 2012; 142(4): 973-81. http://journal.publications.chestnet.org/article.aspx?articleid=1215975