Frequencies for first 10,000 rows of birwt12 variable in natl1990 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          9        0.09        0.09
          2 |         56        0.56        0.65
          3 |         69        0.69        1.34
          4 |        142        1.42        2.76
          5 |        509        5.09        7.85
          6 |      1,804       18.04       25.89
          7 |      3,564       35.64       61.53
          8 |      2,801       28.01       89.54
          9 |        877        8.77       98.31
         10 |        142        1.42       99.73
         11 |         17        0.17       99.90
         12 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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