Frequencies for first 10,000 rows of pbamorer variable in namcs2009 dataset :

  percent pop w/bachelor's degree or |
             higher in patient's zip |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                        missing data |        541        5.41        5.41
quartile 1 (less than 12.84 percent) |      2,084       20.84       26.25
    quartile 2 (12.84-19.66 percent) |      2,075       20.75       47.00
    quartile 3 (19.67-31.68 percent) |      2,743       27.43       74.43
  quartile 4 (31.69 percent or more) |      2,557       25.57      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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