The statistics used to track the share of income going to the top 1% have been criticized by Alan Reynolds. He points out that the Tax Reform Act of 1986 changed the way that income is defined on tax returns, which is the primary source of data utilized to compile income shares. Among these changes includes the fact that beginning in the 1980s, many C-Corporations switched to S-Corporations, which changed the way that their income is reported on income tax returns. S-Corporations report all income on the individual income tax returns of the owners, while C-Corporations file a separate tax return and corporate profits are not allocated to any individuals. Prior to 1986, approximately one fourth of all American corporations were S-Corporations, but by 1997 this share had risen to more than half. In addition, by 2001 S-Corporations were responsible for about 25% of before-tax profits.