How can I convert (or switch) the RGB percent values from the LR histogram into RGB values which are shown e. g. in PS/CameraRAW?

Question

In LR 5.5 (same in previous versions) the RGB values in the histogram are shown in percent (relativ) values. I prefere to see the absolute values, but I can`t find any way to switch. Maybe this option is intentional disabled, because LR works in 16-Bit mode this would result in values up to 2^16. But as i compared the relativ values from LR with the absolute values from PS i run into a conversion problem. The following example shows the differences:
CameraRAW : RGB, 128,0,0
Lightroom: RGB, 43,8%, 19,0%, 6,2%
CameraRAW: RGB, 0,128,0
Lightroom: RGB, 29,8%, 47,5%, 17,5%
Mainly i have two questions:
1. Is there any possibility to change the percent RGB values in LR to absolut values?
2. How can i convert CameraRAW values to LR values (see above)?

Answer 1

TThe reason that a design decision was made from the beginning of LR to show only the percentage values was that RGB values are dependent on the color space and the LR histogram and numerical readout are derived from the Develop module's display space which is a hybrid color space with ProPhoto RGB primaries and the sRGB TRC. Thus the numerical values in the display would be different from the exported RGB image (in an orthodox space) and it was feared that this would be misleading. When soft proofing was introduced, because it involved converting the display to an orthodox space, it became possible to use the 0-255 scale in that mode.