Frequencies for first 10,000 rows of birwt12 variable in natl1997 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         23        0.23        0.23
          2 |         72        0.72        0.95
          3 |         92        0.92        1.87
          4 |        178        1.78        3.65
          5 |        534        5.34        8.99
          6 |      1,871       18.71       27.70
          7 |      3,770       37.70       65.40
          8 |      2,545       25.45       90.85
          9 |        758        7.58       98.43
         10 |        141        1.41       99.84
         11 |         14        0.14       99.98
         12 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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