Frequencies for first 10,000 rows of nlbnd variable in natlterr1999 dataset :

  Number of |
Live Births |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,848       98.48       98.48
          1 |        134        1.34       99.82
          2 |         11        0.11       99.93
          3 |          4        0.04       99.97
         10 |          2        0.02       99.99
         99 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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