2017 25.69
2016 NA
2015 24.78
2014 25.3981927710843
2013 25.0429530201342
2012 24.1161290322581
2011 25.7290502793296
2010 26.3345403899721
2009 25.6956164383562
2008 25.2688034188034
2007 26.0020202020202
2006 25.6865771812081
2005 25.9018404907975
2004 25.5034482758621
2003 24.2090425531915
2002 25.568152866242
2001 25.3838323353293