Frequencies for first 10,000 rows of isllb17 variable in natl1978 dataset :

   Interval |
 since last |
 live birth |
  Recode 17 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,266       42.66       42.66
          1 |         94        0.94       43.60
          2 |         85        0.85       44.45
          4 |        317        3.17       47.62
          5 |        355        3.55       51.17
          7 |        298        2.98       54.15
          8 |        284        2.84       56.99
         10 |        620        6.20       63.19
         11 |        508        5.08       68.27
         12 |        925        9.25       77.52
         13 |        618        6.18       83.70
         14 |        464        4.64       88.34
         16 |        358        3.58       91.92
         17 |        203        2.03       93.95
         18 |        144        1.44       95.39
         19 |        117        1.17       96.56
         20 |        256        2.56       99.12
         21 |         88        0.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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