Frequencies for first 10,000 rows of ssamsasz variable in pos2010 dataset :

    SSA MSA |
  SIZE CODE |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      3,210       32.10       32.10
          A |      1,261       12.61       44.71
          B |      2,507       25.07       69.78
          C |        843        8.43       78.21
          D |      1,221       12.21       90.42
          E |        814        8.14       98.56
          F |        144        1.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017