Frequencies for first 10,000 rows of tbskin variable in nhamcsopd1995 dataset :

    tb skin |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,870       98.70       98.70
          1 |        130        1.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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