Year	Percent change (Units)
1980	2.898
1981	2.512
1982	1.495
1983	-0.729
1984	3.204
1985	1.947
1986	0.424
1987	3.641
1988	2.998
1989	5.614
1990	7.711
1991	1.642
1992	3.579
1993	2.314
1994	5.894
1995	9.593
1996	9.092
1997	10.747
1998	8.765
1999	10.530
2000	9.404
2001	5.306
2002	5.899
2003	3.014
2004	6.789
2005	5.739
2006	4.988
2007	5.311
2008	-4.484
2009	-5.095
2010	1.682
2011	1.281
2012	-0.129
2013	1.175
2014	8.829
2015	24.475
2016	1.766
2017	9.311
2018	8.471
2019	5.298
2020	6.617
2021	15.125
2022	9.433
2023	-3.199
2024	1.466
2025	2.453
2026	2.507
2027	2.513
2028	2.517
2029	2.522