Frequencies for first 10,000 rows of copd variable in nhamcsed2013 dataset :

       Does |
    patient |
      have: |
    Chronic |
obstructive |
  pulmonary |
    disease |
     (COPD) |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,717       97.17       97.17
        Yes |        283        2.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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