This is interesting, but I'm already suspicious of your measurements. What exactly are you measuring?
Usually, when someone measures how low to the ground a shoe is, they're measuring the from the ground to where the foot sits. I don't know of any tennis shoe that has the human heel sitting 3.45mm off of the ground. These measurements are best done with a caliper that measures the thickness of the outsole, the midesole, and insole so that you can tell the "stack" height.
Are you measuring some sort of curve of the outsole when a foot isn't in the shoe flattening it out?