Frequencies for first 10,000 rows of ob_srvc_cd variable in pos2000 dataset :

       srv: |
 obstetrics |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,871       88.71       88.71
          0 |        549        5.49       94.20
          1 |        542        5.42       99.62
          2 |         28        0.28       99.90
          3 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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