Frequencies for first 10,000 rows of skin variable in nhamcsopd1997 dataset :

  skin exam |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,353       93.53       93.53
          1 |        647        6.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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