Year	Percent change (Units)
1981	-5.208
1982	0.963
1983	3.164
1984	-1.548
1985	6.720
1986	5.291
1987	7.790
1988	10.870
1989	8.364
1990	-2.300
1991	-6.900
1992	9.455
1993	16.687
1994	12.877
1995	8.232
1996	7.119
1997	16.115
1998	9.828
1999	10.968
2000	19.883
2001	2.301
2002	4.081
2003	-0.626
2004	8.363
2005	5.728
2006	11.752
2007	9.437
2008	0.308
2009	-22.372
2010	5.520
2011	0.102
2012	-0.608
2013	0.041
2014	-2.700
2015	-3.648
2016	2.952
2017	8.800
2018	0.815
2019	3.936
2020	-4.527
2021	5.549
2022	2.089
2023	0.317
2024	0.336
2025	3.200
2026	3.400
2027	3.300
2028	3.250
2029	3.200