Year	Percent change (Units)
1980	18.345
1981	20.243
1982	17.189
1983	10.397
1984	8.636
1985	5.468
1986	3.041
1987	3.154
1988	2.166
1989	3.990
1990	3.357
1991	3.132
1992	3.150
1993	1.418
1994	2.366
1995	2.518
1996	2.180
1997	1.253
1998	2.130
1999	2.412
2000	5.303
2001	3.998
2002	4.686
2003	4.000
2004	2.310
2005	2.201
2006	2.674
2007	2.889
2008	3.119
2009	-1.676
2010	-1.636
2011	1.213
2012	1.892
2013	0.538
2014	0.301
2015	-0.050
2016	-0.183
2017	0.259
2018	0.716
2019	0.860
2020	-0.443
2021	2.413
2022	8.049
2023	5.209
2024	2.380
2025	2.000
2026	1.950
2027	1.960
2028	1.980
2029	2.000