Frequencies for first 10,000 rows of pbamorer variable in nhamcsopd2010 dataset :

  percent pop w/bachelor's degree or |
             higher in patient's zip |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                        missing data |        404        4.04        4.04
quartile 1 (less than 12.84 percent) |      3,122       31.22       35.26
    quartile 2 (12.84-19.66 percent) |      3,001       30.01       65.27
    quartile 3 (19.67-31.68 percent) |      2,065       20.65       85.92
  quartile 4 (31.69 percent or more) |      1,408       14.08      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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