Frequencies for first 10,000 rows of pct012k055 variable in sf12010880us30 dataset :

   52 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,024       90.24       90.24
          1 |        764        7.64       97.88
          2 |        154        1.54       99.42
          3 |         33        0.33       99.75
          4 |         13        0.13       99.88
          5 |          2        0.02       99.90
          6 |          4        0.04       99.94
          7 |          1        0.01       99.95
          8 |          2        0.02       99.97
          9 |          2        0.02       99.99
         33 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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