Frequencies for first 10,000 rows of pct012k159 variable in sf12010880us30 dataset :

   52 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,993       89.93       89.93
          1 |        761        7.61       97.54
          2 |        163        1.63       99.17
          3 |         48        0.48       99.65
          4 |         18        0.18       99.83
          5 |          4        0.04       99.87
          6 |          3        0.03       99.90
          7 |          5        0.05       99.95
          8 |          3        0.03       99.98
         13 |          1        0.01       99.99
         19 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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