Year	Percent change (Units)
1980	-38.600
1981	-12.000
1982	-12.600
1983	-16.200
1984	-6.600
1985	14.300
1986	5.800
1987	-1.500
1988	-1.000
1989	11.900
1990	-4.800
1991	-4.804
1992	0.164
1993	-18.526
1994	-8.541
1995	7.865
1996	-9.301
1997	-0.740
1998	33.736
1999	10.487
2000	-2.979
2001	-5.539
2002	5.831
2003	4.820
2004	9.242
2005	6.236
2006	8.618
2007	14.016
2008	8.383
2009	6.302
2010	7.603
2011	16.347
2012	11.393
2013	4.916
2014	8.201
2015	1.662
2016	-10.911
2017	-13.161
2018	2.277
2019	5.592
2020	0.207
2021	9.012
2022	19.125
2023	10.506
2024	1.392
2025	2.921
2026	6.277
2027	7.262
2028	8.028
2029	8.424