Frequencies for first 10,000 rows of mm_mtr variable in natl2016 dataset :

   Maternal |
Transfusion |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,907       99.07       99.07
          U |         39        0.39       99.46
          Y |         54        0.54      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 4 Oct 2017