Frequencies for first 10,000 rows of pct012k158 variable in sf12010880us30 dataset :

   51 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,015       90.15       90.15
          1 |        734        7.34       97.49
          2 |        181        1.81       99.30
          3 |         35        0.35       99.65
          4 |         21        0.21       99.86
          5 |          6        0.06       99.92
          6 |          3        0.03       99.95
          7 |          2        0.02       99.97
          8 |          2        0.02       99.99
         20 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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