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region 2 ACARS_TEMPERATURE level 4 nobs_poss 5010 prior 4995 poste 0
level_grand: rmse grand pr = 1.4934; bias grand pr = -0.68356
In comparison 1) the "prior" numbers will differ, and there may be different levels
which have non-0 nobs_poss, which makes comparison trickier.
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