Frequencies for first 10,000 rows of bpap variable in nhamcsed2012 dataset :

  BPAP/CPAP |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,976       99.76       99.76
        Yes |         24        0.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016