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

      Brain |
natriuretic |
    peptide |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,716       97.16       97.16
        Yes |        284        2.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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