Frequencies for first 10,000 rows of prov2070 variable in pos1996 dataset :

       srv: |
 anesthesia |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,803       88.03       88.03
          0 |        389        3.89       91.92
          1 |        420        4.20       96.12
          2 |        340        3.40       99.52
          3 |         48        0.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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