Year	Percent change (Units)
1980	2.614
1981	6.967
1982	16.210
1983	7.997
1984	23.869
1985	8.362
1986	-5.579
1987	17.980
1988	-6.403
1989	-10.300
1990	-19.576
1991	7.859
1992	-12.930
1993	-3.490
1994	-18.289
1995	6.690
1996	1.343
1997	26.197
1998	8.631
1999	14.764
2000	6.372
2001	-0.127
2002	6.378
2003	5.026
2004	8.471
2005	41.341
2006	17.426
2007	2.531
2008	21.122
2009	30.392
2010	22.106
2011	-3.441
2012	27.782
2013	1.057
2014	15.832
2015	33.444
2016	14.505
2017	-3.694
2018	-4.689
2019	-8.815
2020	-4.618
2021	-1.295
2022	7.316
2023	-5.223
2024	13.782
2025	6.316
2026	14.240
2027	10.417
2028	10.901
2029	9.096