Year	Percent change (Units)
1980	1.200
1981	12.167
1982	5.868
1983	8.151
1984	14.317
1985	3.804
1986	1.676
1987	7.113
1988	4.487
1989	11.662
1990	7.002
1991	8.997
1992	1.797
1993	9.657
1994	14.897
1995	19.221
1996	26.512
1997	31.063
1998	12.471
1999	3.522
2000	25.523
2001	7.868
2002	-1.258
2003	10.574
2004	8.177
2005	13.253
2006	2.744
2007	8.412
2008	24.407
2009	10.557
2010	6.496
2011	9.583
2012	18.176
2013	7.938
2014	4.417
2015	5.554
2016	5.526
2017	16.597
2018	-2.767
2019	-0.709
2020	7.305
2021	8.313
2022	18.888
2023	26.955
2024	21.964
2025	19.965
2026	15.978
2027	9.953
2028	9.986
2029	10.020