Frequencies for first 10,000 rows of prov0090 variable in pos1993 dataset :

       ccpd |
certificati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,993       99.93       99.93
          A |          5        0.05       99.98
          B |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016