Frequencies for first 10,000 rows of prov2265 variable in pos1995 dataset :

       srv: |
 obstetrics |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,933       89.33       89.33
          0 |        498        4.98       94.31
          1 |        540        5.40       99.71
          2 |         25        0.25       99.96
          3 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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