I think the average is at least two changes to the final 8 from year to year since 1994 with one top 4 side bombing out the following year too. The comp is so even now that apart from the top 2 and bottom couple any of these middle of the rung sides (like us) could finish anywhere between top 4 and bottom 4. You need a good run with injuries to make the finals and to win the close games.