Frequencies for first 10,000 rows of rf_inftr variable in natl2015 dataset :

Infertility |
  Treatment |
 Used Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,784       97.84       97.84
          U |        108        1.08       98.92
          Y |        108        1.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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