That's going to be a big change going forward. I don't think we'll see too many coaching tenures even 12 years long like Franklin has (at least, at the P4 level).
James Franklin started at Penn State in 2014. There were six FBS head coaches (Kirk Ferentz, Kyle Whittingham, Troy Calhoun, Dabo Swinney, Dave Doeren, Mark Stoops) with more tenure than Franklin (and three - including Miami's Chuck Martin - who started in 2014).