Year	Percent change (Units)
1980	0.000
1981	0.000
1982	0.000
1983	0.000
1984	0.000
1985	0.000
1986	0.000
1987	0.000
1988	0.000
1991	30.131
1992	-4.148
1993	2.308
1994	8.779
1995	-13.438
1996	10.175
1997	11.358
1998	-1.948
1999	6.726
2000	0.951
2001	-32.552
2002	12.168
2003	-4.764
2004	-11.994
2005	-4.097
2006	-8.947
2007	-30.104
2008	-2.156
2009	17.432
2010	15.048
2011	1.608
2012	21.528
2013	26.451
2014	60.168
2015	-4.127
2016	6.299
2017	-7.611
2018	5.845
2019	-23.443
2020	-37.838
2021	33.213
2022	-7.182
2023	21.950
2024	8.723
2025	6.066
2026	6.355
2027	5.485
2028	5.578
2029	6.285