Frequencies for first 10,000 rows of mrcnty variable in natlterr2011 dataset :

   Mother's |
  County of |
  Residence |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,261       12.61       12.61
         10 |      3,294       32.94       45.55
         21 |        238        2.38       47.93
         25 |        181        1.81       49.74
         31 |        207        2.07       51.81
         97 |         83        0.83       52.64
        100 |         43        0.43       53.07
        110 |        952        9.52       62.59
        113 |        193        1.93       64.52
        120 |         38        0.38       64.90
        127 |        449        4.49       69.39
        999 |      3,061       30.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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