Frequencies for areacode variable in zipmil_12q4 dataset : single area | code for | zip code. | Freq. Percent Cum. ------------+----------------------------------- . | 538 100.00 100.00 ------------+----------------------------------- Total | 538 100.00 by Jean Roth , jroth@nber.org , 4 Jan 2016 tail -n+3 /homes/data/zip/sas/2012/desc/zipmil_12q4/byvar/tab/areacode.log | e