Frequencies for first 10,000 rows of no_infec variable in natl2014 dataset :

         No |
 Infections |
 Reported 1 |
       True |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        398        3.98        3.98
          1 |      9,433       94.33       98.31
          9 |        169        1.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016