Frequencies for first 10,000 rows of thorc_srgry_sw variable in pos1994 dataset :

      spec: |
   thoracic |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,575       95.75       95.75
          N |        402        4.02       99.77
          Y |         23        0.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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