Frequencies for first 10,000 rows of ab_nicu variable in natlterr2013 dataset :

  Admission |
to NICU RFP |
630=f_ab_ni |
       cu R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      1,077       10.77       10.77
          N |      8,071       80.71       91.48
          U |        333        3.33       94.81
          Y |        519        5.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015