Frequencies for first 10,000 rows of hincomer variable in nhamcsed2007 dataset :

  median household income in |
          patient's zip code |      Freq.     Percent        Cum.
-----------------------------+-----------------------------------
                missing data |        656        6.56        6.56
  quartile 1 (below $32,793) |      3,353       33.53       40.09
quartile 2 ($32,794-$40,626) |      1,813       18.13       58.22
quartile 3 ($40,627-$52,387) |      2,204       22.04       80.26
quartile 4 ($52,388 or more) |      1,974       19.74      100.00
-----------------------------+-----------------------------------
                       Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016