That's not how the math works.
1% is not a constant value.
1% of 1K = 10
1% of 3K = 30
The question would be: 72 DET = +1%
From what? Current performance? Some hidden base value?
Agreed on the average.
Testing with <100 stat is rather useless because Statistics will likely swallow up most differences (unless you heal 100K times).