Year % 1997 55.1804 1999 55.35007 2000 47.83013 2001 47.70614 2002 45.95636 2003 49.55992 2004 50.98528 2005 52.1564 2006 40.06057 2007 49.69209 2008 52.68445 2009 36.59139 2010 51.99716 2012 37.86812 2013 37.88412 2018 23.72467 2019 26.44248 2020 25.59225 2021 24.53092