Year	Percent change (Units)
1980	-28.942
1981	-29.925
1982	22.205
1983	11.909
1984	16.191
1985	21.989
1986	5.365
1987	18.568
1988	-8.306
1989	-39.838
1990	172.249
1991	50.000
1992	5.000
1993	64.618
1994	36.357
1995	31.643
1996	19.541
1997	-3.345
1998	0.862
1999	-5.478
2000	3.276
2001	3.361
2002	22.095
2003	27.984
2004	33.476
2005	6.692
2006	17.691
2007	33.621
2008	17.762
2009	-7.329
2010	4.247
2011	2.805
2012	13.764
2013	19.620
2014	12.913
2015	16.134
2016	12.855
2017	19.436
2018	9.526
2019	3.684
2020	3.487
2021	18.203
2022	1.743
2023	-6.166
2024	8.759
2025	7.608
2026	8.372
2027	8.042
2028	7.618
2029	7.557