Frequencies for first 10,000 rows of prov1330 variable in pos1991 dataset :

 tech super |
          - |
 hematology |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,698       96.98       96.98
          1 |        237        2.37       99.35
          2 |         54        0.54       99.89
          3 |          4        0.04       99.93
          4 |          5        0.05       99.98
          5 |          1        0.01       99.99
          6 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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