Year	Percent change (Units)
1980	17.359
1981	14.818
1982	11.703
1983	13.121
1984	11.705
1985	22.318
1986	31.945
1987	24.849
1988	19.772
1989	17.651
1990	28.294
1991	14.409
1992	11.221
1993	18.505
1994	10.584
1995	10.030
1996	9.790
1997	4.490
1998	2.549
1999	0.513
2000	2.274
2001	3.745
2002	1.869
2003	2.121
2004	4.452
2005	4.690
2006	4.035
2007	4.580
2008	7.258
2009	0.537
2010	1.179
2011	5.129
2012	1.730
2013	0.758
2014	1.141
2015	-0.731
2016	0.604
2017	1.014
2018	1.088
2019	0.074
2020	-0.370
2021	3.468
2022	7.196
2023	4.047
2024	0.896
2025	1.700
2026	1.750
2027	1.800
2028	1.800
2029	1.800