Frequencies for first 10,000 rows of pbamorer variable in nhamcsopd2006 dataset :

  percent pop w/bachelor's degree or |
        higher in patient's zip code |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
Quartile 1 (Less than 12.84 percent) |      2,667       26.67       26.67
    Quartile 2 (12.84-19.66 percent) |      2,373       23.73       50.40
    Quartile 3 (19.67-31.68 percent) |      2,319       23.19       73.59
  Quartile 4 (31.69 percent or more) |      2,059       20.59       94.18
                        Missing data |        582        5.82      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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