2017 26.4360902255639
2016 26.7225352112676
2015 26.6207282913165
2014 26.3161111111111
2013 26.4008287292818
2012 26.435593220339
2011 26.4744744744745
2010 26.9754874651811
2009 26.5535031847134
2008 26.039527027027
2007 26.351724137931
2006 26.5794871794872
2005 26.6754285714286
2004 26.2929577464789
2003 26.7313888888889
2002 26.5832386363636
2001 26.6145348837209