Frequencies for first 10,000 rows of ob_srvc_cd variable in pos2008 dataset :

       srv: |
 obstetrics |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,655       86.55       86.55
          0 |        715        7.15       93.70
          1 |        574        5.74       99.44
          2 |         36        0.36       99.80
          3 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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