Frequencies for first 10,000 rows of msa variable in namcs2012 dataset :

      Metropolitan Statistical Area |
       Status of physician location |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
MSA (Metropolitan Statistical Area) |      9,614       96.14       96.14
                            Non-MSA |        386        3.86      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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