Frequencies for first 10,000 rows of isllb8 variable in natl1987 dataset :

   Interval |
 since last |
 live birth |
   Recode 8 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,438       44.38       44.38
          1 |        106        1.06       45.44
          2 |         82        0.82       46.26
          3 |      1,310       13.10       59.36
          4 |      1,127       11.27       70.63
          5 |        807        8.07       78.70
          6 |      1,000       10.00       88.70
          7 |      1,067       10.67       99.37
          8 |         63        0.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016