Frequencies for first 10,000 rows of prov1330 variable in pos1995 dataset :

 tech super |
          - |
 hematology |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,783       97.83       97.83
          1 |        172        1.72       99.55
          2 |         35        0.35       99.90
          3 |          6        0.06       99.96
          4 |          3        0.03       99.99
          5 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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