Legal sports betting could add a serious boost to the National Football League’s TV ratings, according to new Nielsen data.

On Thursday, the American Gaming Association (AGA) released the findings of an AGA-commissioned Nielsen Sports survey into the relationship between NFL regular season viewing and sports betting. The survey queried 1,000 US adults along with 500 “pre-qualified NFL bettors” to ensure proper samples.

Nielsen found that bettors watched 19 more NFL games during the 2015 season than non-bettors. Sports bettors made up one-quarter of the total 2015 regular season audience but claimed 47% of all minutes viewed. On average, bettors watched 11 more minutes per game than non-bettors.

Nielsen estimated that the advent of legal sports betting in the US would raise the number of NFL regular season viewers who bet on sports to jump from 40m to 57m. Legal sports betting would result in bettors comprising 36% of the NFL viewing audience and consuming 56% of all minutes viewed.