Frequencies for first 10,000 rows of prov0070 variable in pos1992 dataset :

       capd |
certificati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,983       99.83       99.83
          A |         11        0.11       99.94
          B |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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