Frequencies for first 10,000 rows of metrores variable in natl1976 dataset :

 Met/Nonmet |
  county of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,650       46.50       46.50
          2 |      5,345       53.45       99.95
          Z |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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