Year	Percent change (Units)
1980	-7.000
1981	14.410
1982	15.251
1983	6.236
1984	9.428
1985	-9.747
1986	4.756
1987	10.407
1988	31.155
1989	4.516
1990	8.228
1991	6.560
1992	6.400
1993	16.698
1994	10.415
1995	26.000
1996	18.403
1997	9.626
1998	8.327
1999	7.556
2000	15.874
2001	2.736
2002	1.598
2003	-2.203
2004	5.901
2005	6.613
2006	9.354
2007	2.064
2008	-2.407
2009	-10.881
2010	25.512
2011	9.777
2012	8.040
2013	2.458
2014	7.209
2015	6.152
2016	1.954
2017	2.842
2018	6.972
2019	1.175
2020	-4.878
2021	5.677
2022	8.096
2023	-6.688
2024	1.328
2025	0.714
2026	2.352
2027	3.087
2028	3.092
2029	3.090