Year current US$ 2006 439999.997615814 2007 349999.99403953605 2008 340000.00357627904 2009 140000.000596046 2010 330000.013113022 2011 159999.99642372102 2012 340000.00357627904 2013 289999.99165535 2014 319999.99284744303 2015 419999.986886978 2016 142587.199807167 2017 375572.08538055397 2018 208770.215511322 2019 175154.253840446 2020 200119.823217392 2021 300643.861293793 2022 300856.918096542