Year	Percent change (Units)
1980	15.287
1981	3.968
1982	-5.382
1983	-1.479
1984	3.056
1985	2.620
1986	9.541
1987	-1.384
1988	7.614
1989	15.139
1990	-0.022
1991	4.948
1992	5.932
1993	5.921
1994	17.745
1995	17.955
1996	14.989
1997	16.465
1998	-13.998
1999	-39.849
2000	20.141
2001	-2.862
2002	11.812
2003	8.060
2004	10.064
2005	4.686
2006	14.580
2007	1.183
2008	-3.117
2009	-2.109
2010	17.976
2011	4.454
2012	15.780
2013	0.225
2014	13.695
2015	2.966
2016	9.623
2017	20.450
2018	8.036
2019	5.423
2020	-16.899
2021	6.437
2022	12.607
2023	6.684
2024	-0.967
2025	7.948
2026	8.347
2027	8.515
2028	8.064
2029	4.984