Frequencies for first 10,000 rows of isllb8 variable in natl1980 dataset :

   Interval |
 since last |
 live birth |
   Recode 8 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,326       43.26       43.26
          1 |         92        0.92       44.18
          2 |         64        0.64       44.82
          3 |      1,338       13.38       58.20
          4 |      1,161       11.61       69.81
          5 |        827        8.27       78.08
          6 |      1,036       10.36       88.44
          7 |      1,085       10.85       99.29
          8 |         71        0.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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