With the announcements on Tuesday from Reps. Rush Holt and Gloria Negrete McLeod that they wouldn't seek reelection to the House, the total number of representatives who are planning not to return in 2015 has hit 34, according to the The New York Times. That sounds like a lot. In the recent history of Congress, though, it isn't.

Roll Call has been tracking what it evocatively calls its "Casualty List" since the 93rd Congress, which runs from 1973 to 1975. For this 113th Congress, it has 37 House members who are either retiring, running for another office, or who've been appointed or elected to another position. That's a combined 526 years of experience that won't be back in the House for the 114th Congress. (Average age, if you're wondering: 61.) In total, it's 8.5 percent of the 435-member House.

But that's on the low-end of such figures. Since 1973, 9.6 percent of Congress has willingly moved on in one way or another before the next Congress begins. Here's each percentage, by start year of the Congress.

The high point was in the 1991-1992 Congress, when 16.3 percent of the body left — largely because 52 members announced plans to retire. 52! That makes the 19 current retirements seem like business as usual.

Because it is. I took Roll Call's data since 1973 and broke out three types of departures: people who retired, people who resigned either in disgrace or for another office, and those who ran for another office and won or lost. (I will note here that some members of Congress run for other seats while running for House reelection, so a small, hard-to-extract set of that data will be off.) Here's how those departures have evolved over time.

The graph clearly shows that the number of retirements this year is not terribly unusual for the election.

Nor is it particularly suggestive of what will happen in November. The 1994, 2006, and 2010 "wave" elections, in which a large number of House members lost their seats, don't match evenly with big spikes in retirements. One writer for the conservative site Townhall.com speculated that Democratic retirements "may be a sign that the Democrats see a huge Republican wave election coming in 2014." If it is, it's despite the data. And it's also despite the fact that more Republicans than Democrats have announced plans to retire, 11 to 8.

Until another 30 members of Congress declare that they're not going to run for reelection, the 113th Congress is nothing special in that regard. Like so much else in politics, these minor moments tend to be given much more significance than is warranted.