Frequencies for first 10,000 rows of mar variable in linkpe2009psden dataset :

   Mother's |
    Marital |
 Status U;R |
   (652 rep |
    flag ?) |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      3,787       37.87       37.87
          2 |      6,213       62.13      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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