The original data statistics should be the same for the same area and time selection whether or not the data are smoothed (I.e. don't include the extra years needed to do the smoothing in the reported statistics calculation. Now they can be different. This is the case whether or not there is a Z-Score Transformation
there is a related but separate issue: with smoothed Z score transformed data, using the selected time range vs a fixed time range set to the same values should produce the same result. Now different time ranges are used in the calcuation of the mean and sd for the two cases. Only the years within the interval should be used for mean and SD calculation.
The original data statistics should be the same for the same area and time selection whether or not the data are smoothed (I.e. don't include the extra years needed to do the smoothing in the reported statistics calculation. Now they can be different. This is the case whether or not there is a Z-Score Transformation
there is a related but separate issue: with smoothed Z score transformed data, using the selected time range vs a fixed time range set to the same values should produce the same result. Now different time ranges are used in the calcuation of the mean and sd for the two cases. Only the years within the interval should be used for mean and SD calculation.