People may hate Congress, but they keep sending the same people back to Washington.

Despite historic levels of unpopularity with the legislative branch, turnover in Congress has actually been pretty normal in recent years -- if not on the low side historically.

To be sure, the partisan split in Congress has undergone significant change in recent elections. The three straight wave elections between 2006 and 2010 were the first time that that had happened in half a century.

But even as a significant number of seats have changed partisan hands, overall turnover in Congress (which also includes things like retirements, deaths and primary losses) has actually been pretty par-for-course.

Even the amount of new blood after the 2006 and 2008 elections, in which Democrats picked up a combined 54 House seats, ranked low historically.

The charts below, from the Congressional Research Service, tell the story in the House and the Senate:

The fact is that members used to retire and lose primaries a lot more than they do today. For the vast majority of members, merely running for reelection at all assures that they will return for the next Congress. So why not stick around?

Which means that the Congresses of today include about the same amount of new blood as they used to -- even as people claim to hate everything about the institution.

Dan Keating contributed to this report.