Frequencies for first 10,000 rows of birwt12 variable in natl1992 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         12        0.12        0.12
          2 |         63        0.63        0.75
          3 |         71        0.71        1.46
          4 |        161        1.61        3.07
          5 |        501        5.01        8.08
          6 |      1,768       17.68       25.76
          7 |      3,611       36.11       61.87
          8 |      2,746       27.46       89.33
          9 |        878        8.78       98.11
         10 |        159        1.59       99.70
         11 |         25        0.25       99.95
         12 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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