Frequencies for first 10,000 rows of prov2245 variable in pos1991 dataset :

       srv: |
    nuclear |
   medicine |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,770       87.70       87.70
          0 |        406        4.06       91.76
          1 |        602        6.02       97.78
          2 |        203        2.03       99.81
          3 |         19        0.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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