Frequencies for first 10,000 rows of disllb variable in linkco1991us_num dataset :

   Interval |
 Since Last |
 Live Birth |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,513       55.13       55.13
          1 |        418        4.18       59.31
          2 |         31        0.31       59.62
          7 |      3,621       36.21       95.83
          9 |        417        4.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015