You don't say over what distance the gains are. I suspect that the gains are all based on the same baseline, a standard road bike set up. I imagine each subsequent change would see a % gain but not a simple numerical gain.
But what is interesting is some of the gains compared with others and the difference in costs. Just think a pair of shoe covers makes you faster then a carbon aero frame!
I've got the hat, skin suit and aero bars and my times are "only" slower by about 8 mins from when I used to ride a normal bike. Dread to think what my times would be now if I was still riding the same set up!
Keith