Frequencies for first 10,000 rows of csasc variable in sf12010880us36 dataset :

   Combined |
Statistical |
  Area Size |
       Code |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      4,717       47.17       47.17
         18 |        447        4.47       51.64
         19 |         27        0.27       51.91
         20 |        438        4.38       56.29
         21 |      1,218       12.18       68.47
         22 |        140        1.40       69.87
         23 |      3,013       30.13      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 8 May 2017