Year | Canadaa | Mexico | U.S.A. | Reference |
---|---|---|---|---|
2006 | EU (4/4) | ntb | EU (7/7) | Ling et al., 2008 [17] |
2007 | nt | nt | EU + CH2 (1/1) | |
2009 | nt | 0/10 | EU (4/4) | This study |
2010 | CH2 (4/4) | CH2 (3/3) | CH2 (3/3) | |
2011 | nt | CH2 (5/5) | CH2 (1/1) | |
2012 | CH2 (7/10), US1 + CH2 (3/10) | US1 (14/22), CH2 (6/22), US1 + CH2 (2/22) | CH2 (17/32), CH2 + EU (14/32), EU (1/32) |