Are we benchmarking inverters on the basis of outdated definitions of the european and CEC efficiency?

The formulas for the calculation of the European Efficiency have been developed in 1990. At that time, the irradiance was measured manually every three hours. Out of this data, hourly values were interpolated. The weighting factors for the European Efficiency were calculated with these hourly values. If we recalculate the weighting factors with currently available instantaneous values of the irradiance, different results are achieved.