Year % 1988 1.67 1993 1.91 1995 11.08 1996 10.14 1997 11.35 1998 16.75 1999 12.37 2000 14.78 2001 16.59 2002 13.5 2003 12.58 2004 13.96 2005 14.58 2006 12.47 2007 12.43 2008 12.56 2009 12.97 2010 14.38 2011 15.27 2012 17.46 2013 18.62 2014 19.39 2015 19.3 2016 19.42 2017 18.84 2018 16.19 2019 22.56 2020 16.32 2021 14.67