Year maximum value in 2004 = 100 2006 33.4785669859 2007 34.8240742112 2008 36.3007062184 2009 35.3808802447 2010 36.5482711066 2011 33.9234166429 2012 33.7574497787 2013 35.333560294 2014 35.0932494113 2015 34.4686530123 2016 33.2720236394 2017 44.1530981528 2018 43.1997786955 2019 45.663150413 2020 34.9132492208 2021 32.7069226225