Year current international $ 2000 4.14050766441316 2001 4.85425993424014 2002 4.95095434732616 2003 5.66610789340804 2004 7.87391030201673 2005 6.11020800897515 2006 7.05945911188005 2007 6.9946371258675 2008 4.30668438882406 2009 5.17905021870889 2010 5.68613580187847 2011 6.30434919955776 2012 7.70827782015686 2013 7.63223952543175 2014 10.658998255099 2015 7.49370228359168 2016 8.59493663095073 2017 4.6274838496722 2018 5.04166772526364 2019 5.2125081085384 2020 4.53682690088587 2021 20.4824625886727