Frequencies for first 10,000 rows of prov2440 variable in pos2004 dataset :

       srv: |
  radiology |
(diagnostic |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,766       87.66       87.66
          0 |         20        0.20       87.86
          1 |        860        8.60       96.46
          2 |        218        2.18       98.64
          3 |        136        1.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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