Frequencies for first 10,000 rows of isllb17 variable in natl1980 dataset :

   Interval |
 since last |
 live birth |
  Recode 17 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,326       43.26       43.26
          1 |         92        0.92       44.18
          2 |         64        0.64       44.82
          4 |        315        3.15       47.97
          5 |        354        3.54       51.51
          7 |        360        3.60       55.11
          8 |        309        3.09       58.20
         10 |        607        6.07       64.27
         11 |        554        5.54       69.81
         12 |        827        8.27       78.08
         13 |        612        6.12       84.20
         14 |        424        4.24       88.44
         16 |        295        2.95       91.39
         17 |        226        2.26       93.65
         18 |        178        1.78       95.43
         19 |        125        1.25       96.68
         20 |        261        2.61       99.29
         21 |         71        0.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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