Year % 1989 3.479106 1990 3.290311 1991 3.640425 1992 3.621849 1993 3.649655 1995 2.404806 1996 2.096178 1997 0.022564 1998 2.396659 1999 2.206745 2000 2.083959 2001 1.949744 2002 2.373789 2003 2.088727 2004 2.107989 2005 2.211174 2006 2.123947 2007 2.977224 2008 2.886477 2009 2.777158 2010 2.880878 2011 2.677168 2012 2.685833 2013 2.510761 2014 2.695076 2015 2.734098 2016 2.641872 2017 1.617376 2018 1.42205 2019 1.633823 2020 1.376568 2021 0.4981647