Year maximum value in 2004 = 100 2006 3.0145195804 2007 4.2722167293 2008 4.9603647751 2009 4.9603647751 2010 4.3030751436 2011 4.152441899 2012 4.152441899 2013 4.7567967011 2014 4.7570085411 2015 4.7570085411 2016 6.0437275109 2017 6.4975649119 2018 6.4975649119 2019 6.2067315408 2020 5.0658437666 2021 4.6139440328