@PRIOR Essbase function calculates only one period after each save instead of the 12 periods at once

Dears, this is my essbase code

SET CALCPARALLEL 4;

SET AGGMISSG OFF;

SET UPDATECALC OFF;

SET CACHE HIGH;

SET LOCKBLOCK HIGH;

SET CREATENONMISSINGBLK ON;

FIX (&BudYr, &CurrVersion) 

  FIX ("Plan", "No Department", "No Intercompany", "No Project", "No Detail") 

    FIX (@RELATIVE("YearTotal", 0)) 

      {Entity} (

        IF (@ISMBR("Jan")) 

          "Beginning Cash" = "Net Cash Flow"->"TQF"->"Dec"->&CurrYr;

        ELSE 

      "Beginning Cash" = @PRIOR("Net Cash Flow");

        ENDIF

      ) 

    ENDFIX 

  ENDFIX 

ENDFIX

But instead of calculating the beginning cash for the 12 periods at once , I have to save the data form (which runs the rule) 12 times as it calculates each period separately after each run !!

is there any solution?