Frequencies for low variable in drg1990 dataset :

 Low Volume |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        441       92.26       92.26
          * |         37        7.74      100.00
------------+-----------------------------------
      Total |        478      100.00

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