Year	Percent change (Units)
1980	110.638
1981	36.364
1982	31.111
1983	31.335
1984	48.378
1985	44.506
1986	34.617
1987	38.851
1988	73.668
1989	63.267
1990	60.317
1991	65.967
1992	70.073
1993	66.097
1994	104.540
1995	89.566
1996	80.236
1997	85.653
1998	84.721
1999	64.870
2000	55.035
2001	54.246
2002	45.134
2003	25.337
2004	8.599
2005	8.179
2006	9.597
2007	8.756
2008	10.444
2009	6.251
2010	8.566
2011	6.472
2012	8.892
2013	7.493
2014	8.855
2015	7.671
2016	7.775
2017	11.144
2018	16.332
2019	15.177
2020	12.279
2021	19.596
2022	72.309
2023	53.859
2024	59.520
2025	38.414
2026	22.409
2027	19.018
2028	18.612
2029	18.604