Frequencies for first 10,000 rows of isllb17 variable in natl1976 dataset :

   Interval |
 since last |
 live birth |
  Recode 17 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,444       44.44       44.44
          1 |         83        0.83       45.27
          2 |         91        0.91       46.18
          4 |        322        3.22       49.40
          5 |        318        3.18       52.58
          7 |        321        3.21       55.79
          8 |        313        3.13       58.92
         10 |        593        5.93       64.85
         11 |        546        5.46       70.31
         12 |        904        9.04       79.35
         13 |        639        6.39       85.74
         14 |        486        4.86       90.60
         16 |        242        2.42       93.02
         17 |        200        2.00       95.02
         18 |        121        1.21       96.23
         19 |         87        0.87       97.10
         20 |        196        1.96       99.06
         21 |         94        0.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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