Year	Percent change (Units)
1980	8.576
1981	13.864
1982	2.048
1983	16.459
1984	12.620
1985	1.294
1986	35.025
1987	24.436
1988	10.675
1989	-3.666
1990	5.088
1991	12.222
1992	12.124
1993	10.062
1994	18.098
1995	22.956
1996	10.190
1997	18.714
1998	14.565
1999	12.270
2000	16.985
2001	-1.799
2002	12.813
2003	13.580
2004	21.005
2005	7.899
2006	12.045
2007	12.604
2008	7.602
2009	-0.457
2010	13.028
2011	15.417
2012	5.793
2013	3.820
2014	2.096
2015	0.234
2016	2.372
2017	2.480
2018	3.976
2019	0.238
2020	-1.707
2021	11.095
2022	3.429
2023	3.081
2024	3.660
2025	3.221
2026	3.266
2027	3.229
2028	3.066
2029	3.023