Dragon saving throws

So I’m looking at the high end of the Dragon table, and some of the high power ones have F16, F18, and F20 as their save categories. The fighter save table, however, caps at 14, and in particular, the one on page 108 states that F14+ has the same numbers as F14. So, are F16, F18, and F20 extrapolated from F14 at fighter base +2 per 3 levels, or are they equal to F14? If they are equivalent, why are they written differently?

my take:

The fighter save table, however, caps at 14, and in particular, the one on page 108 states that F14+ has the same numbers as F14.<<
I would say, that this assumes someone of the fighter class only.
extrapolated from F14 at fighter base +2 per 3 levels<<
And since monsters are not actually fighters (i.e. of the fighter class) i would extrapolate for monsters…

It’s intended that you extrapolate by +2 per 3 levels.

OK; that did seem more probable (but holy damn high-power dragons have good saves).