Frequencies for grouperv variable in impact1998 dataset :

    Grouper |
Version for |
       cmiv |      Freq.     Percent        Cum.
------------+-----------------------------------
         15 |      5,182      100.00      100.00
------------+-----------------------------------
      Total |      5,182      100.00

by Jean Roth , jroth@nber.org , 17 Mar 2016