Frequencies for first 10,000 rows of birwt12 variable in natl1991 dataset :

Birthweight |
  Recode 12 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          9        0.09        0.09
          2 |         40        0.40        0.49
          3 |         73        0.73        1.22
          4 |        149        1.49        2.71
          5 |        468        4.68        7.39
          6 |      1,733       17.33       24.72
          7 |      3,647       36.47       61.19
          8 |      2,804       28.04       89.23
          9 |        898        8.98       98.21
         10 |        157        1.57       99.78
         11 |         19        0.19       99.97
         12 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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