Frequencies for first 10,000 rows of pct012m066 variable in sf12010880us32 dataset :

   63 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,922       99.22       99.22
          1 |         76        0.76       99.98
          2 |          1        0.01       99.99
          4 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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