Model Year vs Resale Value (all things being equal)

Went to nadaguides, picked a similar unit (ACE 29.2), same mileage (20000)..... results:

ACE 29.2 14 13 12 11
msrp $101,528 $100,090 $90,053 $89,993

avg ret $79,841 $69,990 $64,731 $59,513
78.64% 69.93% 71.88% 66.13%

low ret 66270 58090 54399 49399
65.27% 58.04% 60.41% 54.89%

So, the unit would appear to be worth (low retail) about 55% after 4 years?

Another thought... if the Hershey show is used to intro the new models, why is the 2015 Axis/Vegas already out and available?

Ed