Frequencies for first 10,000 rows of open_hrt_srgry_srvc_cd variable in pos2009 dataset :

       SRV: |
CARDIO-THOR |
       ACIC |
    SURGERY |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,638       86.38       86.38
          0 |      1,093       10.93       97.31
          1 |        211        2.11       99.42
          2 |         46        0.46       99.88
          3 |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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