Frequencies for first 10,000 rows of birwt12 variable in natlterr1998 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.07        0.07
          2 |         64        0.64        0.71
          3 |         74        0.74        1.45
          4 |        178        1.78        3.23
          5 |        727        7.27       10.50
          6 |      2,684       26.84       37.34
          7 |      4,020       40.20       77.54
          8 |      1,873       18.73       96.27
          9 |        323        3.23       99.50
         10 |         46        0.46       99.96
         11 |          3        0.03       99.99
         12 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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