Year	U.S. dollars (Units)
1992	159.971
1993	174.875
1994	297.162
1995	316.227
1996	411.140
1997	553.468
1998	543.344
1999	576.005
2000	656.386
2001	674.783
2002	760.812
2003	879.863
2004	1039.818
2005	1567.194
2006	2453.261
2007	3813.751
2008	5564.444
2009	4964.696
2010	5880.509
2011	7238.602
2012	7545.553
2013	7926.600
2014	7938.578
2015	5524.527
2016	3897.788
2017	4217.653
2018	4759.796
2019	4841.145
2020	4280.429
2021	5468.269
2022	7822.589
2023	7525.428
2024	7640.915
2025	7808.084
2026	8014.664
2027	8256.333
2028	8548.969
2029	8906.405