Frequencies for first 10,000 rows of ob_srvc_cd variable in pos2005 dataset :

       srv: |
 obstetrics |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,731       87.31       87.31
          0 |        654        6.54       93.85
          1 |        561        5.61       99.46
          2 |         37        0.37       99.83
          3 |         17        0.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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