Frequencies for first 10,000 rows of pbamorer variable in namcs2006 dataset :

  percent pop w/bachelor's degree or |
        higher in patient's zip code |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
quartile 1 (less than 12.84 percent) |      2,511       25.11       25.11
    quartile 2 (12.84-19.66 percent) |      2,192       21.92       47.03
    quartile 3 (19.67-31.68 percent) |      2,487       24.87       71.90
  quartile 4 (31.69 percent or more) |      2,167       21.67       93.57
                        missing data |        643        6.43      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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