Let V be the volume of the region S ⊆ ℝ3 defined by 

S = {(x, y, z) ∈ ℝ3 : xy ≤ z ≤ 4, 0 ≤ x2 + y2 ≤ 1}.

Then \(\frac{V}{\pi}\) is equal to __________. (rounded off to two decimal places)