The average age in the House of Representatives and Senate is 57 and 63, respectively, the highest the chambers' historical offices have on record, USA Today reported Tuesday.

Despite departures of lawmakers such as Republican Sens. Ted Stevens of Alaska and John Warner of Virginia, both octogenarians, the 111th Congress that convened Tuesday is grayer in part because some of its younger members such as 47-year-old Obama moved on, too, the newspaper said.

The oldest member, 91-year-old Democratic Sen. Robert Byrd of West Virginia, returns.

"Even though we're losing a lot of years, a lot still remain," Senate historian Richard Baker said.

All but one of 37 House and Senate committee chairs named so far were in Congress before Obama graduated from Harvard Law School in 1991. Fourteen members arrived in Washington before the incoming president finished high school.

The nation's founders may have wanted an older Congress, USA Today said. The Constitution requires representatives be at least 25 and senators at least 30.

For the record, John F. Kennedy, at 43, was the youngest elected U.S. president, About.com said. Theodore Roosevelt was the youngest man to serve as president when he took over after William McKinley's assassination. He was 42.