Mayo Clinic reports a strong financial performance in 2012 as the Minnesota-based health care provider added more employees and patients.

Mayo reported Wednesday it took in annual revenue of $8.8 billion last year, with expenses of $8.4 billion.

Mayo Clinic has a large presence in three U.S. metropolitan — Rochester, Minn., Jacksonville, Fla., and Scottsdale.

According to the clinic’s annual report, Mayo maintained an operating margin of 4.5 percent which “aligns with the clinic’s long-term objectives” of 4 percent to 6 percent.

The report also aid donations to Mayo dropped for the second year in a row. In 2010, Mayo received nearly $400 million in donations. That dropped to about $320 million in 2011 and about $250 million in 2012.