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

Hepatitis B |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,801       98.01       98.01
          U |        169        1.69       99.70
          Y |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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