Frequencies for first 10,000 rows of pct012k096 variable in sf12010880us30 dataset :

   93 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,980       99.80       99.80
          1 |         18        0.18       99.98
          2 |          1        0.01       99.99
          3 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 8 May 2017