Frequencies for first 10,000 rows of pct013c033 variable in sf12000860us31 dataset :

   21 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,709       87.09       87.09
          1 |        872        8.72       95.81
          2 |        215        2.15       97.96
          3 |         95        0.95       98.91
          4 |         48        0.48       99.39
          5 |         16        0.16       99.55
          6 |         14        0.14       99.69
          7 |          6        0.06       99.75
          8 |          4        0.04       99.79
          9 |          4        0.04       99.83
         10 |          2        0.02       99.85
         11 |          1        0.01       99.86
         13 |          2        0.02       99.88
         16 |          1        0.01       99.89
         18 |          1        0.01       99.90
         19 |          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
         66 |          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