Frequencies for first 10,000 rows of isllb17 variable in natl1981 dataset :

   Interval |
 since last |
 live birth |
  Recode 17 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,400       44.00       44.00
          1 |        100        1.00       45.00
          2 |         95        0.95       45.95
          4 |        289        2.89       48.84
          5 |        354        3.54       52.38
          7 |        372        3.72       56.10
          8 |        300        3.00       59.10
         10 |        657        6.57       65.67
         11 |        505        5.05       70.72
         12 |        819        8.19       78.91
         13 |        540        5.40       84.31
         14 |        367        3.67       87.98
         16 |        319        3.19       91.17
         17 |        205        2.05       93.22
         18 |        160        1.60       94.82
         19 |        127        1.27       96.09
         20 |        285        2.85       98.94
         21 |        106        1.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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