Year maximum value in 2004 = 100 2006 32.7158603686 2007 31.7661304615 2008 25.0204166259 2009 31.4261695324 2010 30.5781719177 2011 38.5994633127 2012 40.4683344606 2013 42.2182467217 2014 46.2843317619 2015 41.1983000124 2016 45.3168939736 2017 48.4963221664 2018 58.5898336811 2019 60.0209156049 2020 60.3079108584 2021 60.1012367189