I have priced the 13 races and variants in the SCAG with this system.
On average they are out by less than 4%
More stats
Mean average: 11.577
Median average: 12.00
Mode Average: 12.00
Standard Deviation: 2.77
Duergar 12, Ghostwise 12,
Half Elf variants: 10, 10, 8.5, 9.5, 10, 17, 8
Tiefling...