Year	U.S. dollars (Units)
1990	1412.471
1991	1537.047
1992	1405.473
1993	1093.836
1994	1212.382
1995	2272.326
1996	2787.957
1997	2947.257
1998	3492.771
1999	2839.043
2000	2902.478
2001	2466.333
2002	3078.446
2003	3549.926
2004	4034.358
2005	4773.442
2006	5545.702
2007	6123.002
2008	7266.624
2009	7864.591
2010	8734.160
2011	8756.276
2012	9767.349
2013	9936.505
2014	9966.713
2015	9036.203
2016	5762.414
2017	6158.572
2018	6772.070
2019	6715.747
2020	4782.092
2021	4987.986
2022	5784.332
2023	5885.181
2024	6702.270
2025	7000.943
2026	7177.885
2027	7462.615
2028	7688.594
2029	8006.500