Year % 1996 0.41 1997 0.43 1998 0.56 1999 0.87 2000 1.47 2002 1.5 2003 1.14 2004 1.45 2005 1.48 2006 1.91 2009 0.71 2010 0.93 2018 1.33 2019 1.35