A circular artery has its diameter reduced to $0\mathrm{.}870$ times its original size. Find the percent increase in the pressure differential required to maintain the original blood flow, Q $($assume Poiseuille's Law applies to circulation in the blood vessels, i$.$e$.$ the flow is laminar and the viscosity is independent of velocity and of the diameter of the artery$).$ Enter the percentage as your answer, for example enter $78\mathrm{.}6$ for $78\mathrm{.}6$ percent.