Frequencies for first 10,000 rows of disllb variable in natl1975 dataset :

   Interval |
 since last |
 live birth |      Freq.     Percent        Cum.
------------+-----------------------------------
        888 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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