Frequencies for first 10,000 rows of pct012e042 variable in sf12000860us20 dataset :

   39 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,727       97.27       97.27
          1 |        250        2.50       99.77
          2 |         21        0.21       99.98
          3 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2017