Frequencies for first 10,000 rows of ctab variable in nhamcsed2015 dataset : CT scan - | abdomen/pel | vis | Freq. Percent Cum. ------------+----------------------------------- No | 9,330 93.30 93.30 Yes | 670 6.70 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 20 Nov 2017