X11 output B 5 - Seasonal Factors

The extreme values in the B 3 series are replaced by the values shown in B 4 . From this X-11 series, preliminary seasonal factors are derived by applying a 5-term moving average to each month separately; then a 12-term moving average is computed for the entire series, and the resulting values adjusted to sum to zero (additive model) or 12.0 (multiplicative model) within each year.
For more information, see X-11 Census Method II Seasonal Adjustment .