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

   percent poverty in patient's zip |
                               code |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                       missing data |        457        4.57        4.57
quartile 1 (less than 5.00 percent) |      1,098       10.98       15.55
     quartile 2 (5.00-9.99 percent) |      2,344       23.44       38.99
   quartile 3 (10.00-19.99 percent) |      3,151       31.51       70.50
 quartile 4 (20.00 percent or more) |      2,950       29.50      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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