Frequencies for first 10,000 rows of ume_vac variable in natlterr2015 dataset :

   Vacuum 1 |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        129        1.29        1.29
          2 |      8,667       86.67       87.96
          9 |      1,204       12.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016