New CivicScience survey data show that about 1 in 5 U.S. adults between the ages of 21 and 54 say they have placed a sports bet online within the past year. This is especially notable given that online sports betting is currently legal in only 14 of the 50 U.S. states.

The most popular type of online bet might be surprising to some. Parlay bets, where the bettor combines two or more separate bets into a single wager, were the most common type of online bet over the past year. Right up there with parlay bets were prop bets, in which the bettor wagers on something other than the game’s final score (e.g., how many points a certain player scores, which team scores first, etc.).

When it comes to what sports Americans are betting on online, it’s no surprise that the NFL takes the top spot. Pro basketball was fairly close behind.

Those ages 21 to 34 were far more likely to bet on sports online than those ages 35 to 54.

Online sports bettors are also more diverse than others their age.

Interestingly, online sports bettors are much more likely than others their age to be occasional cigarette smokers or cannabis users. They’re also more likely to drink beer every now and then.

And, as we’ve noted before, there are strong correlations between online sports betting and fantasy sports, as well as cryptocurrency.

As online sports betting continues to become legal in more and more U.S. states, the percentage of Americans taking part will only grow. CivicScience will keep a pulse on the state of online sports betting as this relatively young market continues to expand.