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

Hepatitis B |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,078       10.78       10.78
          N |      8,789       87.89       98.67
          U |        107        1.07       99.74
          Y |         26        0.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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