Table 1.

Estimated TMRCAs for the PRRSV ORF5 gene sequences isolated within each system.

System	Mean TMRCA*	Lower 95% HPD	Upper 95% HPD
A	Aug-2009	Dec-2007	Aug-2011
B	Aug-2006	Nov-2003	Aug-2009
C	Sep-1996	Jul-1989	Dec-2001
D	Jul-2009	Jan-2007	Aug-2011
E	Jul-2009	Jan-2007	Aug-2011
Overall	Sep-1996	Jul-1989	Dec-2001

^*Time to the most recent common ancestor (TMRCA).