Frequencies for first 10,000 rows of prov1405 variable in pos1994 dataset :

technologis |
 t - 90 hrs |
 + training |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,953       99.53       99.53
          1 |         35        0.35       99.88
          2 |          5        0.05       99.93
          3 |          1        0.01       99.94
          4 |          1        0.01       99.95
         10 |          2        0.02       99.97
         20 |          2        0.02       99.99
         30 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017