Frequencies for first 10,000 rows of pct012k188 variable in sf12010880us30 dataset :

   81 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,784       97.84       97.84
          1 |        189        1.89       99.73
          2 |         19        0.19       99.92
          3 |          4        0.04       99.96
          4 |          1        0.01       99.97
          5 |          2        0.02       99.99
          7 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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