Frequencies for first 10,000 rows of msa variable in nhamcsopd2008 dataset : msa or non-msa area | Freq. Percent Cum. ------------------------------------+----------------------------------- msa (metropolitan statistical area) | 8,737 87.37 87.37 non-msa | 1,263 12.63 100.00 ------------------------------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016