Frequencies for first 10,000 rows of birwt12 variable in natlterr1996 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.07        0.07
          2 |         43        0.43        0.50
          3 |         62        0.62        1.12
          4 |        172        1.72        2.84
          5 |        724        7.24       10.08
          6 |      2,522       25.22       35.30
          7 |      4,062       40.62       75.92
          8 |      1,967       19.67       95.59
          9 |        384        3.84       99.43
         10 |         48        0.48       99.91
         11 |          5        0.05       99.96
         12 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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