Year % 1996 41.66371 1999 31.69732 2001 36.59583 2002 38.08651 2003 37.00827 2006 34.12496 2007 42.19947 2008 42.63124 2009 37.8268 2010 37.74722 2011 43.07118 2012 32.59534 2013 41.51487 2014 41.51487 2015 40.96245 2016 38.83313 2017 38.82883 2018 30.45621 2019 31.53096 2020 30.55314 2021 30.93474