Frequencies for first 10,000 rows of biopsy variable in nhamcsopd2010 dataset : biopsy | Freq. Percent Cum. ------------+----------------------------------- no | 9,806 98.06 98.06 yes | 194 1.94 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016