Iowa ranks 35th out of the 50 states and Washington, D.C., for growth in number of middle-market firms from 2011 to 2016, according to the latest Middle Market Power Index from American Express and Dun & Bradstreet. The state has an estimated 2,044 middle-market companies, defined as having annual revenues between $10 million and $1 billion. While the total number of all commercially active firms in the United States declined between 2011 and 2016, the number of middle-market firms nearly doubled, with an increase of 87 percent, the report said. In that same period, the number of middle-market firms in Iowa increased 76.5 percent. Since 2011, U.S. middle-market companies have outpaced both smaller businesses (less than $10 million in revenues) and the largest companies (more than $1 billion in revenues) in both employment and revenue growth.