For examination point of view, how do I find the enthalpy and entropy for the 90 bar and 16 bar pressure if I don't have their tables? Also how do we attempt this question. Please detail out all the steps. I would really appreciate

An HP turbine receives steam from a boiler at 90bar and 500C and expands to a pressure of 16 bar and enters a reheater at 16 bar and 270C. Pressure drops to 15 bar in the reheater and reheated steam at 500C enters the LP turbine and finally gets exhausted to a condenser pressure of 0.04 bar. Assuming steam consumption of 3kg/kWh, generator efficiency of 94 per cent and heat lost through the turbine casing as 1 per cent of throttle enthalpy, determine the efficiency of the turbine