Frequencies for first 10,000 rows of petscan variable in nhamcsopd2007 dataset :

   pet scan |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,988       99.88       99.88
        yes |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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