Let \( B \) be the centre of the circle \( x^{2}+y^{2}-2x+4y+1=0 \). Let the tangents at two points \( P \) and \( Q \) on the circle intersect at the point \( A(3,1) \). Then \( 8\left(\dfrac{\text{area } \triangle APQ}{\text{area } \triangle BPQ}\right) \) is equal to ______.
