Frequencies for first 10,000 rows of birwt4 variable in linkco1991us_num dataset :

      Birth |
     Weight |
   Recode 4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,710       47.10       47.10
          2 |      1,518       15.18       62.28
          3 |      3,549       35.49       97.77
          4 |        223        2.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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