Frequencies for first 10,000 rows of pct012k137 variable in sf12010880us30 dataset :

   30 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,230       92.30       92.30
          1 |        589        5.89       98.19
          2 |        115        1.15       99.34
          3 |         42        0.42       99.76
          4 |         16        0.16       99.92
          5 |          2        0.02       99.94
          6 |          1        0.01       99.95
          7 |          1        0.01       99.96
          8 |          1        0.01       99.97
         10 |          1        0.01       99.98
         11 |          1        0.01       99.99
         28 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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