Frequencies for first 10,000 rows of msa variable in nhamcsopd2011 dataset :

                MSA or non-MSA area |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
MSA (Metropolitan Statistical Area) |      9,193       91.93       91.93
                            Non-MSA |        807        8.07      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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