Frequencies for first 10,000 rows of mammo variable in nhamcsopd2006 dataset :

mammography |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,836       98.36       98.36
        Yes |        164        1.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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