Frequencies for first 10,000 rows of metro variable in mort1975 dataset :

      metro |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      6,705       67.05       67.05
          2 |      3,275       32.75       99.80
          Z |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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