Frequencies for first 10,000 rows of mrcityfips variable in natl2003 dataset :

   Mother's |
   Place of |
  Residence |
 (FIPS) U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
       3000 |      4,265       42.65       42.65
       7000 |          2        0.02       42.67
      51000 |          4        0.04       42.71
      99999 |      5,729       57.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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