Frequencies for first 10,000 rows of prov2705 variable in pos1991 dataset :

      staff |
   assisted |
   dialysis |
       cert |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,571       95.71       95.71
          A |        290        2.90       98.61
          B |        136        1.36       99.97
          E |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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