Frequencies for first 10,000 rows of strep variable in namcs1999 dataset : strep test | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,904 99.04 99.04 1 | 96 0.96 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016