Frequencies for first 10,000 rows of pctpovr variable in nhamcsopd2008 dataset :

   percent poverty in patient's zip |
                               code |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                       missing data |        473        4.73        4.73
quartile 1 (less than 5.00 percent) |      1,832       18.32       23.05
     quartile 2 (5.00-9.99 percent) |      2,393       23.93       46.98
   quartile 3 (10.00-19.99 percent) |      3,017       30.17       77.15
 quartile 4 (20.00 percent or more) |      2,285       22.85      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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