A couple of nits.
Westminster lists their endowment as $100m on their website.
Kent School awards 29% of its students needs-based financial aid. They also award merit-based aid. I suspect that 15% or more of the students get merit-based aid, and that is how you and they get the 44% number.
Kent actually gives a smaller percentage of their students needs-based aid than most peers, who offer needs-based aid to about 33-37% of their students.