Year	Percent change (Units)
1980	4.622
1981	-12.975
1982	-15.185
1983	-8.705
1984	-51.631
1985	-34.913
1986	15.627
1987	14.363
1988	-10.578
1989	22.892
1990	14.057
1991	-53.839
1992	82.740
1993	14.212
1994	47.095
1995	35.723
1996	7.392
1997	-2.149
1998	3.047
1999	5.050
2000	3.624
2001	5.626
2002	-1.635
2003	21.246
2004	6.052
2005	8.748
2006	22.077
2007	8.609
2008	10.736
2009	-32.234
2010	-11.974
2011	4.131
2012	14.336
2013	4.992
2014	3.648
2015	3.876
2016	5.702
2017	11.442
2018	39.070
2019	-11.182
2020	-16.320
2021	7.671
2022	18.323
2023	26.425
2024	5.373
2025	3.509
2026	3.609
2027	3.619
2028	2.373
2029	2.495