In 2005, the IRS launched a study to assess the reporting compliance of S corporations The study began in late 2005 and examined 5,000 randomly selected S corporation returns from tax years 2003 and 2004. The IRS intends to use the results to measure compliance in recording of income, deductions and credits from S corporations, and to formulate future audit criteria to better target likely non-compliant returns. This is part of a larger IRS effort to improve tax compliance and reduce the estimated $300 billion gap in gross reported figures each year. A large portion of that gap is thought to come from small businesses (and particularly S corporations, which are now the most common corporate entity, numbering over 4 million in 2011, up from 3 million in 2002 and about 750,000 in 1985).