Refer to Table 1.A(a) in each Party’s CRF to see if they have reported their activity data based on the NCV or GCV or S&A Tables for the Energy Sector. Also refer to their national inventory report to determine the calorific basis for any energy specific emission factors and activity data used in calculating CO2 emissions from fuel combustion. The difference between the net and the gross calorific value of a fuel is the heat of condensation of the moisture produced from combustion of the fuel. The IEA assumes that the net calorific values are 5 per cent lower than gross calorific values for oil and coal, and 10 percent lower for natural gas.