Frequencies for first 10,000 rows of thorc_srgry_sw variable in pos1995 dataset :

      spec: |
   thoracic |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,552       95.52       95.52
          N |        423        4.23       99.75
          Y |         25        0.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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