Frequencies for first 10,000 rows of bonedens variable in nhamcsopd2007 dataset : bone | mineral | density | Freq. Percent Cum. ------------+----------------------------------- no | 9,969 99.69 99.69 yes | 31 0.31 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016