Congress is losing some of its longest-serving members to retirement this November -- including Rep. John Dingell (D-Mich.) who has been in the House since 1955. But where does the rate of retirements in the 113th Congress rank in comparison to recent years? We did some digging to answer that question.

Sen. Tom Harkin (D-Iowa), one of dozens of long-timers hanging it up after this year. (Susan Walsh/AP)

Here's the current tally of retirements.

And here's how it compares to 2012 and 2010.

Remember, even though there were only 27 retirements in the 111th Congress, it was an especially notable cycle for comings and goings, mostly because several senior members died or took positions in the Obama administration, which led to several appointments to higher office and several members to campaign for new jobs. Eventually, 56 members lost reelection as part of the tea party-fueled wave.

Beyond the raw totals, another way to track the effect of retirements is by tallying the cumulative number of years served.

This year's total number of years served in the House trails the 2012 cycle, even though the 2014 retiring class will include three longtime members -- Reps. George Miller (D-Calif.) and Henry Waxman (D-Calif.), with 40 years of service each, and Dingell, with a whopping 58 years of service.

This year's retiring class of senators definitely outranks previous cycles thanks to the collective departure of several senior Democrats: Sens. Max Baucus (Mont.), Tom Harkin (Iowa), Tim Johnson (S.D.), Carl Levin (Mich.) and Jay Rockefeller (W.Va.). They all chair major committees and have served since the late 1970s or 1980s. Baucus and Levin are leaving after 36 years each, while Harkin and Rockefeller will have served 30.

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