Frequencies for first 10,000 rows of ab_nicu variable in natlterr2014 dataset :

  Admission |
  to NICU Y |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,077       10.77       10.77
          N |      8,291       82.91       93.68
          U |         98        0.98       94.66
          Y |        534        5.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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