Critical Reasoning

Hi,

I have a doubt in the following cr question (Screen of question and explanation attached)

Im not satisfied with the explanation.

The explanation says that ans E is correct. I had chosen ans C.

I juggled between C and E, but ultimately settled for C due to the following reasons:

1. If the number of "RESIDENTS" has remained the same, it would mean that the same people more or less are still resident in the town of Eastbury.
2. Owing to that, given that there are no triggers, the per-capita should remain approximately the same, since the salary of the SAME RESIDENTS would be around the same range as 2 years back.
3. So the primary reason for a differential in after-tax income for the residents must be the tax-cuts imposed by the Senator.

My reasons for rejecting choice E were:
1. The recent change in estate laws does not say how recent were the laws.
2. It says nothing for the demographic of the population. Higher income families might have moved in and lower income moved out.

To me, the choice E did not seem as conclusive as choice C.

Can anyone help me with the reasoning given in the explanation?