Frequencies for first 10,000 rows of birwt12 variable in natl1975 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          3        0.03        0.03
          2 |         45        0.45        0.48
          3 |         58        0.58        1.06
          4 |        146        1.46        2.52
          5 |        513        5.13        7.65
          6 |      1,897       18.97       26.62
          7 |      3,776       37.76       64.38
          8 |      2,652       26.52       90.90
          9 |        705        7.05       97.95
         10 |        126        1.26       99.21
         11 |         17        0.17       99.38
         12 |         62        0.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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