(CNN) -- Rep. John Dingell of Michigan became the longest-serving member of Congress on Friday with 57 years, five months, 27 days and counting on Capitol Hill. His longevity record eclipses that of the late Sen. Robert Byrd of West Virginia. Here's a look at congressional tenure, by the numbers: 9.1 years: Average length of service in the United States House of Representatives as of January 2013, according to the Congressional Research Service. 10.2 years: Average length of service in the U.S. Senate as of January 2013. 13.4 years: Peak average length of service in the House in the 111th Congress(2009-2010).
@highlight
Rep. John Dingell became longest-serving member of Congress on Friday
@highlight
Dingell's record eclipses that of former Sen. Robert Byrd of West Virginia
@highlight
Contrast that with the 60 days that Dean Barkley served to finish Paul Wellstone's term
@highlight
Dingell and his father, John Dingell Sr., served a total of 80 years in Congress
He was appointed to the seat of Sen. @placeholder, who was killed in a plane crash in 2002.