Frequencies for first 10,000 rows of prov2440 variable in pos2009 dataset :

       SRV: |
  RADIOLOGY |
(DIAGNOSTIC |
          ) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,638       86.38       86.38
          0 |         63        0.63       87.01
          1 |        913        9.13       96.14
          2 |        225        2.25       98.39
          3 |        161        1.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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