The studies conducted 10 years ago shows that the feeling of belonging to the group is very weak among the members. We have no evidence that the feeling _____ in the meanwhile.
I want to say that there is no evidence that now there is more feeling of belonging among the members compared to 10 years ago. What verb to use. Is "to increase" idiomatic for feeling? What about "to raise"? Or there is better options? Or maybe such meaning is better be told in a different way like:
We have no evidence of any raise in the feeling of belonging among the member.