Frequencies for first 10,000 rows of endoscop variable in nhamcsopd2001 dataset :

  endoscopy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,961       99.61       99.61
          1 |         39        0.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016