The Fortune 500 is an annual list compiled and published by Fortune magazine that ranks the top 500 U.S. closely held and public corporations as ranked by their gross revenue after adjustments made by Fortune to exclude the impact of excise taxes companies incur. The list includes publicly and privately held companies for which revenues are publicly available. The first Fortune 500 list was published in 1955. Although the Fortune 500 list is the most familiar one, similar gross revenue lists of the top firms range from the highest ranking Fortune 100 including the top one hundred to the broader ranking Fortune 1000 that includes the top thousand firms. While membership on the smaller lists is somewhat stable, the ranking on the lists may change over time depending upon revenues, and often because of mergers among firms already listed. The original Fortune 500 was restricted to companies whose revenues were derived from manufacturing, mining, or energy exploration. At the same time, Fortune published companion “Fortune 50” lists of the 50 largest commercial banks (ranked by assets), utilities (ranked by assets), life insurance companies (ranked by assets), retailers (ranked by gross revenues) and transportation companies (ranked by revenues). Fortune magazine changed its methodology in 1994 to include service companies. With the change came 291 new entrants to the famous list including three in the Top 10. The concept of the Fortune 500 was created by Edgar P. Smith, a Fortune editor.