Frequencies for first 10,000 rows of OB_SRVC_CD variable in pos2011 dataset :

   Services |
  Provided: |
 Obstetrics |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,614       86.14       86.14
          0 |        768        7.68       93.82
          1 |        557        5.57       99.39
          2 |         35        0.35       99.74
          3 |         26        0.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Apr 2019