Turnout in this year’s presidential election is expected to be down slightly from 2008, making it the first presidential election since 1996 in which fewer voters showed up to the polls than did four years ago.

About 129 million voters cast ballots in Tuesday’s presidential election, according to preliminary estimates from Edison Media Research, which conducts the national exit poll. That’s about 2 million fewer votes than 2008, when roughly 131 million people voted.

Turnout has been on the rise in each of the previous three presidential elections. The last time it dropped was between 1992 and 1996, when Bill Clinton won reelection against Bob Dole. It also dipped a bit in the 1988 contest between George H.W. Bush and Michael Dukakis, when compared to Ronald Reagan’s 1984 landslide reelection win over Walter Mondale.

The estimated 129 million people who turned out this year represents about 61 percent of the voting-eligible population (VEP). That’s largely in line with 2008, when 61.6 percent of the VEP cast ballots. (A very handy historical turnout breakdown with more detail can be found here, courtesy of the United States Elections Project at George Mason University.)

One more noteworthy tidbit from Edison Media Research. About 9 million votes are yet to be counted — mostly in California, New York, and Washington. Since these are all states that favor President Obama, his victory in the popular vote could be closer to 51-48 percent than the current 50-48 percent estimate.