This is a good question, and it is dificult to answer with just a number:
If however, I had to pick some numbers, they would be: NSD <4% and LSD <8%.
The problems, past the degree of processing, are things like volume and timing. Certainly, we cannot consume a high starch food and then lower the percentage by consuming a large volume of low starch foods. Overeaters get arthritis at much higher rates than the general population, and this is one contributing reason.
And, we have a moving target: As our tract begins to heal, some of us can 'get away' with a few adventures into starchville's suburbs with impunity--that is why we are constantly 'expermenting.'
Best to You,
"Any teacher who can be replaced by a machine, should be."
Isaac Asimov, 'Project Hole-in-the Wall'