Coaches are most at risk for a concussion, but other players are more likely to suffer a concussion than anyone else, according to the NFL.

According to the most recent concussion survey conducted by the league, just under one in four of the 1,100 players surveyed had suffered a concussion.

And that was during the 2015 season.

That is more than double the average for the previous two seasons combined.

There are other factors at play.

The study surveyed coaches, trainers, medical personnel, medical staff, and a player’s family.

But it does not consider injuries to the brain, which is an important factor for determining if a concussion will result in long-term neurological damage.

The NFL did not respond to a request for comment.

In a statement, the league noted that it has “taken several steps to improve the safety of our players and our fans.”

The league is also working to improve communication between players and the coaches, it said.

The new survey also finds that more than a quarter of players reported they have experienced symptoms of concussions in the last year.

That includes a significant percentage of players who have played in the past year and a half.

There is no single cause for a concussions, but some factors could be at play, according.

For instance, the number of concussive hits per game in the NFL has increased from fewer than 10 a year ago to more than 20 a year, according the survey.

And the frequency of concussed plays is up.

The survey was conducted by ESPN and the National Center for Chronic Traumatic Encephalopathy (NCTEM) at Columbia University, and the data was analyzed by Dr. Michael Mancuso, director of the Center for Neurobehavioral Neuroimaging and Neuroimmunology at Columbia.

The study included players from seven NFL teams.

The survey has not been peer-reviewed, and data is not public.