Frequencies for first 10,000 rows of thorc_srgry_sw variable in pos2000 dataset :

      spec: |
   thoracic |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,327       93.27       93.27
          N |        626        6.26       99.53
          Y |         47        0.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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