Frequencies for first 10,000 rows of bwimp variable in natlterr1996 dataset :

    Imputed |
Birthweight |      Freq.     Percent        Cum.
------------+-----------------------------------
        879 |          1        0.01        0.01
       1446 |          1        0.01        0.02
       3374 |          1        0.01        0.03
       3714 |          1        0.01        0.04
          . |      9,996       99.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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