Frequencies for first 10,000 rows of pct012c128 variable in sf12000860us18 dataset :

   21 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,627       86.27       86.27
          1 |        907        9.07       95.34
          2 |        243        2.43       97.77
          3 |        102        1.02       98.79
          4 |         49        0.49       99.28
          5 |         17        0.17       99.45
          6 |         18        0.18       99.63
          7 |          8        0.08       99.71
          8 |          5        0.05       99.76
          9 |          4        0.04       99.80
         10 |          4        0.04       99.84
         11 |          2        0.02       99.86
         13 |          2        0.02       99.88
         16 |          1        0.01       99.89
         18 |          1        0.01       99.90
         20 |          1        0.01       99.91
         21 |          1        0.01       99.92
         22 |          1        0.01       99.93
         34 |          1        0.01       99.94
         36 |          1        0.01       99.95
         37 |          1        0.01       99.96
         53 |          1        0.01       99.97
         60 |          1        0.01       99.98
         68 |          1        0.01       99.99
         69 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 Apr 2017