Frequencies for first 10,000 rows of prov1250 variable in pos1993 dataset :

technicians |
-high sch + |
   training |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,958       99.58       99.58
          1 |         28        0.28       99.86
          2 |         10        0.10       99.96
          3 |          2        0.02       99.98
          4 |          1        0.01       99.99
         14 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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