Year % 1999 0 2000 0 2001 0 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2013 0 2015 0 2017 1.070316 2018 0.8893185 2019 0.9155223 2020 0.9136212 2021 0.8925056