Frequencies for first 10,000 rows of pct012k156 variable in sf12010880us30 dataset :

   49 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,962       89.62       89.62
          1 |        781        7.81       97.43
          2 |        166        1.66       99.09
          3 |         58        0.58       99.67
          4 |         16        0.16       99.83
          5 |          8        0.08       99.91
          6 |          5        0.05       99.96
          7 |          1        0.01       99.97
          8 |          1        0.01       99.98
         10 |          1        0.01       99.99
         18 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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