Frequencies for first 10,000 rows of copd variable in nhamcsopd1996 dataset :

       does |
    patient |
have - copd |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,799       97.99       97.99
          1 |        201        2.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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