Frequencies for first 10,000 rows of pct012m137 variable in sf12000860us28 dataset :

   30 years |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,737       97.37       97.37
          1 |        232        2.32       99.69
          2 |         26        0.26       99.95
          3 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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