Year % 1997 10.206896551724142 1998 10.919540229885062 2000 11.585365853658539 2001 12.28284059737885 2002 13.466711499663752 2003 13.708836239010584 2004 14.735467015022865 2005 16.237014236244715 2006 16.639209225700167 2007 17.30646601198827 2008 17.800845828527493 2009 18.464052287581694 2010 18.737166324435318 2011 20.53516631889039 2012 21.375802349521617 2013 22.45702005730659 2014 22.15804350497726 2015 23.636991028295373 2016 23.810068649885586 2017 24.01693215996436 2018 24.074279995552104 2019 24.078116025272838 2020 24.868590117976883 2021 25.92505302851757 2022 26.33820651548291 2023 27.033997655334115