Frequencies for first 10,000 rows of spiro variable in nhamcsopd2007 dataset : spirometry/ | pulmonary | function | Freq. Percent Cum. ------------+----------------------------------- no | 9,961 99.61 99.61 yes | 39 0.39 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016