Year	U.S. dollars (Units)
1980	19426.638
1981	17699.844
1982	18027.725
1983	17865.396
1984	17019.366
1985	17187.864
1986	24529.567
1987	30520.621
1988	32794.286
1989	31440.365
1990	39842.782
1991	39811.005
1992	40883.180
1993	39375.507
1994	43226.544
1995	50290.894
1996	48166.173
1997	41625.286
1998	42724.488
1999	41762.292
2000	38978.168
2001	39829.568
2002	42656.086
2003	49516.640
2004	54774.352
2005	56383.878
2006	59220.710
2007	65366.908
2008	74662.365
2009	71894.922
2010	76825.669
2011	90944.046
2012	86284.413
2013	87873.590
2014	89276.302
2015	84231.634
2016	82575.989
2017	82588.943
2018	85547.272
2019	84474.293
2020	86105.978
2021	93707.186
2022	93676.912
2023	100413.067
2024	105668.981
2025	108602.544
2026	113415.756
2027	116978.372
2028	122106.972
2029	125914.284