Frequencies for first 10,000 rows of tz variable in nsrd dataset :

    Station |
Time Zone ( |
 EST = -5 ) |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016