Summary statistics for sf12010zcta5distance500miles dataset :

by Jean Roth , jroth@nber.org , 4 Jan 2016

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
        zip1 |          0
        zip2 |          0
 mi_to_zcta5 |507,778,234    468.0946    205.2658   .0493327    804.672

by Jean Roth , jroth@nber.org , 4 Jan 2016