Frequencies for first 10,000 rows of gmtoffset variable in zipcode dataset :

 diff (hrs) |
between gmt |
   and time |
   zone for |
   zip code |      Freq.     Percent        Cum.
------------+-----------------------------------
         -5 |      9,808       98.08       98.08
         -4 |        192        1.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 4 Jan 2016
 tail -n+3 /homes/data/zip/sas/2013/desc/zipcode/byvar/tab/gmtoffset.log | egre