What are the relative braking contributions from wheel brakes, spoilers and thrust reversers? What is the relative contribution to braking forces in a typical large commercial aircraft  from the three different devices contributing to braking after touchdown:


Wheel brakes
Speed brakes / Spoilers
Reverse Thrusters


The relative contribution should change with velocity so even nicer if we have the velocity depended thrust contributions. e.g. Reverse Thrusters provide more braking at the initial high velocity part of the roll out. 

I'm posting a illustrative (but totally made-up) graph to clarify for what I was looking for:



I am looking for either empirical data or theoretical predictions for the thrust. Qualitatively I'd expect the spoiler contribution to fall off with a square law dependence on velocity. I'd think the reverse thrust offers a somewhat constant component but perhaps higher initially due to parasitic drag by the clamshells? Not sure, and this is what I'm trying to get: A quantitative relationship. 

In case the answer will vary hugely depending on aircraft, I'm open to any specific case being illustrated. 

Let's use the limiting case of full brakes with anti skid on. 

PS. Since spoilers directly add to drag as well as indirectly help braking by dumping lift teasing out their braking thrust contribution might be harder?
Your question shows that you understand the issue already very well, and more detailed fractions of the single components depend on the particular airframe and engine, so my answer will not add much insight.

The only detail I can add is a plot of tire friction coefficient over speed. Unfortunately, I do not know the source of it; I collected it sometime in the past and never found a reason to doubt its validity. 


Also, this document might be helpful. Below I copied Figure 3 from it, because it comes closest to answering your question. But keep in mind that the details depend on the particular aircraft and its systems, as well as runway condition, wind speed, tire and brake condition.



Typical deceleration forces during landing roll, from this document. Note that the aerodynamic drag with spoilers plus reverse thrust at high speed produce already more deceleration than what is desired at low auto brake setting.

In order to find the overall contribution of each braking component, compare the areas under their respective plot lines.