Frequencies for first 10,000 rows of ip_chlam variable in natlterr2015 dataset :

Chlamydia Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,078       10.78       10.78
          N |      8,635       86.35       97.13
          U |        107        1.07       98.20
          Y |        180        1.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016