Consider the surge drum in the figure. Initially the system is at steady-state with a hold-up V̅ = 5 m³, which is 50% of full tank capacity, V_full, and volumetric flow rates F̅_in = F̅_out = 1 m³ h⁻¹. The high hold-up alarm limit V_high = 0.8 V_full while the low hold-up alarm limit V_low = 0.2 V_full. A proportional (P-only) controller manipulates the outflow to regulate the hold-up V as F_out = K_c(V − V̅) + F̅_out. At t = 0, F_in increases as a step from 1 m³ h⁻¹ to 2 m³ h⁻¹. Assume linear control valves and instantaneous valve dynamics. Let K_cmin be the minimum controller gain that ensures V never exceeds V_high. The value of K_cmin, in h⁻¹, rounded off to 2 decimal places, is _________