Year	Percent change (Units)
1997	7.053
1998	10.824
1999	11.040
2000	4.474
2001	3.404
2002	5.416
2003	6.958
2004	7.483
2005	6.179
2006	8.778
2007	10.975
2008	5.548
2009	2.986
2010	11.241
2011	2.041
2012	-1.373
2013	2.372
2014	1.952
2015	4.879
2016	1.832
2017	6.716
2018	1.515
2019	6.997
2020	2.405
2021	13.940
2022	9.847
2023	0.437
2024	4.000
2025	3.698
2026	3.000
2027	3.000
2028	3.000
2029	3.000