Frequencies for first 10,000 rows of ab_nicu variable in natlterr2007 dataset :

  Admission |
to NICU RFP |
630=f_ab_ni |
       cu R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          N |      3,496       34.96       96.59
          U |          1        0.01       96.60
          Y |        340        3.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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