Frequencies for first 10,000 rows of catscan variable in nhamcsopd2011 dataset :

    CT Scan |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,720       97.20       97.20
        Yes |        280        2.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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