Frequencies for first 10,000 rows of ssamsasz variable in pos2009 dataset :

    SSA MSA |
  SIZE CODE |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      3,160       31.60       31.60
          A |      1,339       13.39       44.99
          B |      2,507       25.07       70.06
          C |        843        8.43       78.49
          D |      1,207       12.07       90.56
          E |        801        8.01       98.57
          F |        143        1.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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