Frequencies for first 10,000 rows of papunsp variable in nhamcsopd2009 dataset : pap - | unspecified | Freq. Percent Cum. ------------+----------------------------------- no | 9,940 99.40 99.40 yes | 60 0.60 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016