As an exception to the retired-number policy, MLB began honoring Robinson by allowing players to wear number 42 on April 15, Jackie Robinson Day, which is an annual observance that started in 2004. For the 60th anniversary of Robinson's major league debut, MLB invited players to wear the number 42 on Jackie Robinson Day in 2007. The gesture was originally the idea of outfielder Ken Griffey, Jr., who sought Rachel Robinson's permission to wear the number. After Griffey received her permission, Commissioner Bud Selig not only allowed Griffey to wear the number, but also extended an invitation to all major league teams to do the same. Ultimately, more than 200 players wore number 42, including the entire rosters of the Los Angeles Dodgers, New York Mets, Houston Astros, Philadelphia Phillies, St. Louis Cardinals, Milwaukee Brewers, and Pittsburgh Pirates. The tribute was continued in 2008, when, during games on April 15, all members of the Mets, Cardinals, Washington Nationals, and Tampa Bay Rays wore Robinson's number 42. On June 25, 2008, MLB installed a new plaque for Robinson at the Baseball Hall of Fame commemorating his off-the-field impact on the game as well as his playing statistics. In 2009, all of MLB's uniformed personnel (including players) wore number 42 on April 15; this tradition has continued every year since on that date.