Light Source in Sphere

A closed, hollow, opaque, non-reflective container has the shape of a unit-sphere centered on the origin in the $xyz$ coordinate system.

There is an isotropic light source positioned within the sphere at $(x,y,z) = \Big( \frac{1}{2}, \frac{1}{2}, \frac{1}{2} \Big)$ . What fraction of the total emitted power is incident on the half of the sphere which has negative $x$ coordinates?

If this fraction is $\alpha$ , where $0 < \alpha < 1$ , give your answer as $\lfloor 1000 \, \alpha \rfloor$ .