The NPDC ideal curve in FanGraph of G7

CHROMiX Curve
1

The “G7 How To Document” mentioned GanGraph concept.
I have a question about NPDC ideal curve for CMY or K

How to obtain these points? is it lookup a table or by calculate?
thanks

2

You can download the fangraph here:

idealliance.org/downloads/g7-fangraph-2009