Year	U.S. dollars (Units)
1980	12529.348
1981	10366.108
1982	9128.584
1983	8626.160
1984	8244.846
1985	8568.653
1986	11873.806
1987	14740.456
1988	16008.638
1989	16098.158
1990	20119.935
1991	20563.729
1992	22823.029
1993	21723.624
1994	23624.467
1995	28458.469
1996	27535.287
1997	24878.749
1998	25399.222
1999	25309.057
2000	23136.511
2001	23067.163
2002	25044.331
2003	30707.665
2004	35497.552
2005	36945.499
2006	38841.785
2007	44496.791
2008	48493.137
2009	44892.228
2010	44448.170
2011	47564.381
2012	44824.163
2013	46848.612
2014	47897.037
2015	41147.261
2016	42076.398
2017	44274.073
2018	47685.347
2019	46783.103
2020	45636.457
2021	52026.031
2022	50259.448
2023	53659.317
2024	55536.223
2025	56886.597
2026	58428.977
2027	59965.531
2028	61694.553
2029	63346.238