Frequencies for low variable in drg1991 dataset :

 Low Volume |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        453       92.45       92.45
          * |         37        7.55      100.00
------------+-----------------------------------
      Total |        490      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016