From year to year, some teams improve and some teams do not. Let’s assume that 1/2 of the teams rise in the rankings from one year to the next (24 teams). So after two years 12 teams should have improved over this span (1/2)*(1/2)*48.
It turns out that only 5 teams have shown consecutive improvement from 2007 to 2008 to 2009. One possibility is that if a 4A western team gets blowout out in the finals (2009 IC High 42 Marshalltown 14), all western teams get downgraded 28 points and correcspondingly a lot of positions. So perhaps for classes 3A-A, with their vast network of inter-connected games, this is a more meaningful report.
Nonetheless, here are the 5 4A teams:
Team 07 08 09 Davenport Central 41 41 22 DM Roosevelt 43 43 42 Pleasant Valley 32 30 24 Urbandale 36 16 11 WDM Dowling 17 3 2
So what about 2006? Did any teams have a 3 year run?
Team 06 07 08 09 Davenport Central 45 41 41 22 Pleasant Valley 40 32 30 24 Urbandale 37 36 16 11
And 2005?
Team 05 06 07 08 09 Urbandale 38 37 36 16 11
Urbandale is the current leader of long-range improvement. After mainly top-half finishes early in the decade ( 01 #15, 02 #21, 03 #18, 04 #25), Urbandale found a bottom in 2005 at #38. Since then they have had continuous improvement.
Honorable mention:
Team 05 06 07 08 09 Marshalltown 40 35 18 19 12 CR Washington 15 14 7 8 5