Frequencies for first 10,000 rows of prov2440 variable in pos1998 dataset :

       srv: |
  radiology |
(diagnostic |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,805       88.05       88.05
          0 |         21        0.21       88.26
          1 |        878        8.78       97.04
          2 |        189        1.89       98.93
          3 |        107        1.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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