Year % 1988 70.80219 1989 70.00498 1990 70.67404 1992 70.97585 1995 54.36372 1996 55.04464 1997 55.04464 1998 55.04464 1999 60 2000 60.70679 2001 60.76766 2002 52.39804 2003 52.70748 2005 36.79183 2006 36.86274 2008 37.46096 2009 37.05309 2010 38.58863 2011 37.44978 2013 42.23442 2014 39.20902 2015 33.86807 2016 33.80262 2020 52.83568 2021 50.91523