Politico's Kyle Cheney noticed something interesting about Donald Trump's big primary wins on Tuesday night. With a number of states still to vote — including the largest, California — Trump is poised to set a new record vote total in Republican presidential primaries. The current record is held by George W. Bush, with his 10.8 million votes in 2000. Trump, according to RealClearPolitics, is currently at a little north of 10 million.

But there's a catch: One of the main reasons that Trump has so many votes is that this election has seen so many more voters.

Using data from the Congressional Quarterly Guide to Elections, Real Clear Politics and U.S. Election Atlas, we put together this look at each Republican contest since 1952. Listed is the top vote-getter that year (not always the nominee) and the total number of votes cast.

Unsurprisingly, incumbents get fewer votes because why bother going out to vote for the sitting president to be renominated? But notice, too, that the overall vote totals have increased over time. That's in part a function of the increased role of primaries in the nomination process, and in part a function of America's growing population. (America is more than twice the size now that it was in 1950.)

The fact that the contest isn’t yet settled also plays to Trump’s advantage. Just as there’s less interest in coming out to vote for an incumbent, there’s also less interest in coming out to vote for (or against) the guy that you know already won. As such, turnout drops off significantly once a race is effectively over.

The little pie charts make the percentage of votes won by the leading candidate each year slightly more obvious. Trump won a smaller percentage of all of those votes than did Bush, which he will happily point out is a function of his running against 16 other candidates. But had there not been so many candidates, it's hard to know if there would have been as many votes.

So, yes, Trump will probably set a new record for total votes. But he'll also probably end up as the highest-vote-getting candidate with the lowest percentage of the vote since 1968. That year, the top vote-getter only got about 38 percent of all of the votes cast — thanks to winning his home state of California. That candidate didn't become president in 1968, since Richard Nixon won more states and more delegates.

Instead, Ronald Reagan had to wait until 1980.