Frequencies for first 10,000 rows of prov1355 variable in pos1993 dataset :

 tech super |
     - oral |
  pathology |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,977       99.77       99.77
          1 |         12        0.12       99.89
          2 |          5        0.05       99.94
          3 |          5        0.05       99.99
          4 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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