Frequencies for first 10,000 rows of birwt4 variable in natl1995 dataset :

Birthweight |
   Recode 4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        161        1.61        1.61
          2 |        669        6.69        8.30
          3 |      9,168       91.68       99.98
          4 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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