Pull Your Fair Share (Part 2)

Consider a solid sphere of radius $R$ and uniform mass density. We measure the gravitational field strength at a test point located a distance of $d = 2 R$ from the center of the sphere.

What percentage of the field comes from the outer half of the sphere by radial distance, i.e. from the part where $\frac{R}{2}\leq \text{(distance from center)} \leq R\,?$

Note: There is no ambient gravity.