Year	Percent change (Units)
1980	5.019
1981	7.920
1982	8.235
1983	10.645
1984	22.106
1985	18.320
1986	56.556
1987	23.712
1988	11.549
1989	8.255
1990	12.168
1991	8.642
1992	9.484
1993	6.466
1994	1.710
1995	6.981
1996	1.099
1997	2.781
1998	1.114
1999	3.807
2000	0.851
2001	4.492
2002	8.610
2003	17.032
2004	14.287
2005	4.959
2006	2.056
2007	5.370
2008	4.451
2009	4.554
2010	5.049
2011	4.796
2012	4.645
2013	5.241
2014	6.262
2015	6.808
2016	7.225
2017	8.049
2018	6.521
2019	7.116
2020	5.931
2021	7.370
2022	11.513
2023	16.966
2024	15.123
2025	10.523
2026	6.550
2027	5.000
2028	5.000
2029	5.000