Year	Percent change (Units)
1996	14.314
1997	10.213
1998	11.913
1999	0.224
2000	14.527
2001	16.495
2002	12.169
2003	23.811
2004	10.008
2005	11.565
2006	8.500
2007	6.607
2008	15.052
2009	13.930
2010	11.816
2011	10.287
2012	11.979
2013	7.961
2014	7.978
2015	9.554
2016	18.546
2017	15.368
2018	11.442
2019	11.982
2020	15.754
2021	15.625
2022	21.345
2023	28.921
2024	23.958
2025	19.000
2026	17.000
2027	14.000
2028	14.000
2029	14.000