DxOMark's measured ISOs vs. manufacturer ISOs

It's been stated numerous times in this forum that certain manufacturers overstate their ISOs in order to make their cameras seem to have better noise performance than they actually do.  Out of curiosity, I took a sample (non-scientific) of 22 tested cameras from 8 manufacturers on DxOMark, divided their measured ISO by the manufacturer ISO, and took the average of the results across the tested ISO range.

The number reflects what percentage the measured ISO is to the manufacturer ISO.  In the one case (GH-1) where the percentage exceeds 100%, the measured ISO was higher than the manufacturer ISO.  In all other cases it was lower.  The two worst offenders were the Olympus OM-D E-M5 and the Fuji X100.

Canon:

7D: 78%

5D Mark III: 85% (if removing ISO 50 as an outlier, it would be 78%)

6D: 83% (if removing ISO 50 as an outlier, it would be 76%)

Fuji:

X100: 50% (if removing ISO 3200 and 6400 as outliers, it would be 63%

X10: 99%

(no data available on X-Trans sensor cameras)

Nikon:

D7000: 83%

D800: 78% (if removing ISO 50 as an outlier, it would be 70%)

D600: 85% (if removing ISO 50 as an outlier, it would be 77%)

Olympus:

E-P1: 71%

E-P3: 64%

OM-D E-M5: 49%

Panasonic:

GH-1: 138%

GH-2: 98%

GH-3: 64% (if removing ISO 12800 and 25600 as outliers, it would be 74%)

Pentax:

K-x: 89%

K-7: 85%

K-5: 91%

Samsung:

NX100: 77%

NX200: 85%

Sony:

NEX-5N: 69%

NEX-6: 75%

NEX-7: 81%