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

        urban-rural classification of |
                   patient's zip code |      Freq.     Percent        Cum.
--------------------------------------+-----------------------------------
                  Large central metro |      2,611       26.11       26.11
                   Large fringe metro |      2,230       22.30       48.41
                         Medium metro |      2,684       26.84       75.25
                          Small metro |        736        7.36       82.61
Non-metro (micropolitan and non-core) |      1,332       13.32       95.93
                         Missing data |        407        4.07      100.00
--------------------------------------+-----------------------------------
                                Total |     10,000      100.00

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