Frequencies for first 10,000 rows of hincomer variable in nhamcsopd2009 dataset :

    recoded median household |
income in patient's zip code |      Freq.     Percent        Cum.
-----------------------------+-----------------------------------
                missing data |        456        4.56        4.56
  quartile 1 (below $32,793) |      3,457       34.57       39.13
quartile 2 ($32,794-$40,626) |      2,496       24.96       64.09
quartile 3 ($40,627-$52,387) |      1,902       19.02       83.11
quartile 4 ($52,388 or more) |      1,689       16.89      100.00
-----------------------------+-----------------------------------
                       Total |     10,000      100.00

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