Year	Percent change (Units)
1991	44.913
1992	51.200
1993	61.746
1994	71.277
1995	63.892
1996	38.785
1997	4.635
1998	11.542
1999	7.909
2000	10.964
2001	11.916
2002	12.239
2003	10.831
2004	12.490
2005	9.867
2006	10.845
2007	7.905
2008	18.976
2009	3.675
2010	11.175
2011	19.544
2012	9.885
2013	10.968
2014	8.159
2015	22.000
2016	21.300
2017	30.400
2018	33.645
2019	15.689
2020	21.673
2021	31.464
2022	29.511
2023	-1.225
2024	16.909
2025	17.273
2026	13.663
2027	11.176
2028	10.000
2029	10.000