Year current US$ 1993 450.9800763444843 1994 329.22418198196465 1995 398.1136140940935 1996 454.3766497708706 1997 516.1286022854548 1998 423.4037111859899 1999 387.6894379520276 2000 556.8842529784877 2001 527.4641105187699 2002 872.6576313635089 2003 982.8055874491714 2004 1254.6961186129993 2005 1900.7238092379355 2006 2597.963586638595 2007 3121.34872503374 2008 4081.717506261822 2009 3123.6988851737356 2010 3586.6636935862075 2011 4608.155165726827 2012 5083.826873467353 2013 5061.349252974844 2014 5011.984427453595 2015 3217.339240054168 2016 1809.7093771945495 2017 2439.37443934002 2018 2540.508878845456 2019 2191.3477643353726 2020 1450.9051113941755 2021 1927.4740782768733 2022 2933.48464381415 2023 2309.5216202979054