Frequencies for first 10,000 rows of birwt12 variable in natl1989 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.07        0.07
          2 |         43        0.43        0.50
          3 |         83        0.83        1.33
          4 |        160        1.60        2.93
          5 |        489        4.89        7.82
          6 |      1,760       17.60       25.42
          7 |      3,635       36.35       61.77
          8 |      2,764       27.64       89.41
          9 |        865        8.65       98.06
         10 |        168        1.68       99.74
         11 |         21        0.21       99.95
         12 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016