There is a wide gap between the 10 NFL stadiums built between 1998 and 2002 compared to the newer ones.

The Colts (Lucas Oil), Cowboys (AT&T), Jets and Giants (MetLife), 49ers (Levi’s), Vikings (U.S. Bank), Falcons (Mercedes-Benz), Rams and Chargers (SoFi) and Raiders (Allegiant) all opened new stadiums since 2008.

“What we find is that we’re constantly in a re-adaptation of these venues. Constantly,” said Scott Radecic, a former NFL linebacker and founder and senior principal at architectural design firm Populous. “When you think about how fan behavior changes, when you think about how the rules of the game change and it could create a different type of environment, or you think about just how people’s expectations as we move through years, decades, as we get older, millennials, Gen-Z’ers, you think about different demographic groups, people’s expectations change.”

The club level changed stadiums with Joe Robbie Stadium in Miami in 1987. It helped fund the stadium and began to offer premium seats at a better sight line instead of the first row.

No NFL teams are currently planning to build a new stadium, but owners can renovate.