Year % 1997 19.42 1999 19.54 2000 4.72 2001 4.59 2002 3.99 2003 3.52 2004 3.19 2005 4.29 2006 3.85 2007 2.54 2008 4.99 2009 4.72 2010 4.73 2012 4.07 2013 4.16 2018 11.82 2019 24.56 2020 7.89 2021 7.73