Frequencies for first 10,000 rows of isllb10 variable in natl1980 dataset :

   Interval |
 since last |
 live birth |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,326       43.26       43.26
          1 |         92        0.92       44.18
          2 |         64        0.64       44.82
          3 |        669        6.69       51.51
          4 |        669        6.69       58.20
          5 |      1,161       11.61       69.81
          6 |        827        8.27       78.08
          7 |        612        6.12       84.20
          8 |        424        4.24       88.44
          9 |      1,085       10.85       99.29
         10 |         71        0.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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