Year	Percent change (Units)
1980	10.400
1981	4.577
1982	3.799
1983	-10.300
1984	-5.751
1985	-4.119
1986	-3.279
1987	-4.562
1988	-3.920
1989	-0.830
1990	1.509
1991	3.112
1992	10.093
1993	-0.669
1994	3.567
1995	3.810
1996	7.134
1997	7.523
1998	8.125
1999	8.025
2000	6.901
2001	3.698
2002	7.152
2003	13.878
2004	7.328
2005	5.895
2006	14.181
2007	4.255
2008	3.286
2009	-4.823
2010	3.461
2011	-0.192
2012	5.352
2013	3.532
2014	3.854
2015	-0.777
2016	-7.527
2017	-4.801
2018	-0.602
2019	0.361
2020	-9.078
2021	-1.037
2022	1.482
2023	2.103
2024	2.363
2025	2.307
2026	0.861
2027	2.212
2028	2.889
2029	2.787