Frequencies for first 10,000 rows of msa variable in nhamcsopd2010 dataset :

                msa or non-msa area |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
msa (metropolitan statistical area) |      8,363       83.63       83.63
                            non-msa |      1,637       16.37      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016