Frequencies for first 10,000 rows of birwt12 variable in natl2001 dataset :

      Birth |
     Weight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         18        0.18        0.18
          2 |         67        0.67        0.85
          3 |         97        0.97        1.82
          4 |        181        1.81        3.63
          5 |        565        5.65        9.28
          6 |      2,008       20.08       29.36
          7 |      3,771       37.71       67.07
          8 |      2,502       25.02       92.09
          9 |        664        6.64       98.73
         10 |        108        1.08       99.81
         11 |         13        0.13       99.94
         12 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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