Not a perfect solution I will give you, but did you try with having a summary search first and if people want details they can drill down then ? (I did not test on my side).
I see, you want a sum on the sums. I won't be helpful in this one sorry I feel that it's a "bug" from NetSuite here. I mean it's technically not a bug but it's indeed not helpful to add percents this way. I believe Excel would do the same thing.
Maybe you would have to have two saved searches. There are some crazy formulas out there to "join" two results together.
6969 divided by 227674 = 0.03 = 3%.
3+7+3+2+1+3+0+0+0+1+1+1+1+1 = 30 is not ideal for my case
After contacting NetSuite support, this issue has been filed as an Enhancement case:
163996 Ability to have Formula Total at the bottom of the search behave like Apply Formula to Grand Total in Report