Year	Percent change (Units)
1980	7.052
1981	16.560
1982	26.230
1983	20.571
1984	10.054
1985	10.243
1986	21.113
1987	20.957
1988	11.907
1989	6.213
1990	6.650
1991	7.370
1992	17.029
1993	15.270
1994	16.013
1995	17.406
1996	14.905
1997	26.080
1998	15.217
1999	6.059
2000	4.520
2001	16.609
2002	-5.787
2003	6.424
2004	8.652
2005	9.522
2006	18.904
2007	12.099
2008	10.739
2009	11.993
2010	2.170
2011	33.278
2012	3.617
2013	14.079
2014	12.626
2015	6.214
2016	14.900
2017	1.640
2018	4.550
2019	8.605
2020	-16.232
2021	7.819
2022	21.211
2023	8.790
2024	3.929
2025	7.753
2026	8.160
2027	8.830
2028	10.122
2029	12.129