Frequencies for first 10,000 rows of isllb17 variable in natl1979 dataset :

   Interval |
 since last |
 live birth |
  Recode 17 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,361       43.61       43.61
          1 |         83        0.83       44.44
          2 |         94        0.94       45.38
          4 |        297        2.97       48.35
          5 |        344        3.44       51.79
          7 |        332        3.32       55.11
          8 |        343        3.43       58.54
         10 |        616        6.16       64.70
         11 |        494        4.94       69.64
         12 |        850        8.50       78.14
         13 |        617        6.17       84.31
         14 |        431        4.31       88.62
         16 |        322        3.22       91.84
         17 |        235        2.35       94.19
         18 |        167        1.67       95.86
         19 |        112        1.12       96.98
         20 |        245        2.45       99.43
         21 |         57        0.57      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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