Frequencies for first 10,000 rows of isllb10 variable in natl1976 dataset :

   Interval |
 since last |
 live birth |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,444       44.44       44.44
          1 |         83        0.83       45.27
          2 |         91        0.91       46.18
          3 |        640        6.40       52.58
          4 |        634        6.34       58.92
          5 |      1,139       11.39       70.31
          6 |        904        9.04       79.35
          7 |        639        6.39       85.74
          8 |        486        4.86       90.60
          9 |        846        8.46       99.06
         10 |         94        0.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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