Despite talk of concussion concerns, don't be fooled into thinking it's single-handedly driving down high school football participation. The number of kids playing the game has declined in recent years, but it's largely due to shifting demographics.

And the participation rate is still higher than it was as far back as 1980. Here's what the numbers show:

Since 2003, the number of schools fielding 11-man football teams has held steady, but the number of players has dropped by about 4,000, according to data from the National Federation of State High School Associations.

But this decline mirrors a similar drop in the state's high-school-age population. There are about 11,000 fewer boys ages 14-17 now than there were in 2003.

Population projections indicate there will likely be a slight increase in this age group around 2021, according to the Minnesota State Demographic Center.

In order to see if there has been a decline in participation that might be due to something other than population change, it's necessary to calculate a per capita rate. We used population estimates of boys ages 14-17 to calculate participation rates per 100 boys for football and other high school sports.

Granted, this is not a perfect analysis because the participation statistics come from surveys voluntarily submitted by schools, and it's possible some boys might be slightly younger or slightly older. (We did not count girls who participate in football. In 2015-16, the most recent year of data, there were none reported. The prior year there were five.)

With these caveats in mind, we can see that the football rate has fallen slightly since 2003, but it remains higher than it was in 1980 and 1990 when it was about 14 or 15 per 100. (Keep in mind: Football's participation rate is higher than other sports largely because the teams field more players.)

Is the slight decline in football's participation rate in recent years due to parental (or student) concerns about concussions? Or is it due to students choosing other sports? Or are more kids sitting out high school sports for other reasons?

There has been a lot of public discussion about concussions in football as a potential deterrent.

In a 2014 study of concussion reports at 36 metro area high schools, the Minnesota Department of Health found that football and ice hockey (girls' and boys') had the highest concussion rates, at about 6 per 100 athletes.

The report estimated that during the 2013-2014 school year, 1,355 concussions were reported among football players.

The participation rate data does show increases in other fall sports, such as soccer and cross country. But we don't know whether those students chose those sports over football.

Some spring boys' sports are also increasing, according to NFHS data. Outdoor track, which typically has larger teams than other sports, has seen substantial growth. Baseball has increased slightly since 2003.

The state has about 84 schools that play 9-man football, a number largely unchanged since 2003. However, participation has fallen off at a similar pace as 11-man football.

Ethan Nelson is a University of Minnesota student reporter on assignment for Star Tribune.

Data Drop is a weekly feature that uses data analysis and visualizations to explain, surprise, inform and entertain readers on topics relevant to Minnesotans. Do you have an idea you'd like us to explore? Contact MaryJo Webster