Frequencies for first 10,000 rows of nuclr_mdcn_srvc_cd variable in pos1993 dataset : srv: | nuclear | medicine | Freq. Percent Cum. ------------+----------------------------------- | 8,856 88.56 88.56 0 | 374 3.74 92.30 1 | 578 5.78 98.08 2 | 174 1.74 99.82 3 | 18 0.18 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 17 May 2017