A cylindrical tank with a diameter of 500 mm contains water (density = 1 g·cm⁻³) up to a height h. A 5 mm diameter round nozzle, whose center is 1 cm above the base of the tank, has its exit open to the atmosphere as shown in the schematic below. The pressure above the water level in the tank is maintained at 2 bar (absolute). Neglect all frictional and entry/exit losses. Use acceleration due to gravity as 10 m·s⁻² and atmospheric pressure as 1 bar. The absolute value of initial dh/dt (in mm·s⁻¹) when h = 51 cm is equal to ________ (rounded off to two decimal places).