Frequencies for first 10,000 rows of ssamsasz variable in pos1999 dataset :

    ssa msa |
  size code |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      2,662       26.62       26.62
          A |      1,560       15.60       42.22
          B |      2,933       29.33       71.55
          C |        792        7.92       79.47
          D |      1,190       11.90       91.37
          E |        728        7.28       98.65
          F |        135        1.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016