Frequencies for first 10,000 rows of ssamsasz variable in pos1991 dataset :

    ssa msa |
  size code |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      2,261       22.61       22.61
          A |      1,704       17.04       39.65
          B |      3,285       32.85       72.50
          C |        735        7.35       79.85
          D |      1,132       11.32       91.17
          E |        789        7.89       99.06
          F |         94        0.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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