Year	Percent change (Units)
1991	97.821
1992	150.261
1993	118.612
1994	105.616
1995	70.799
1996	85.612
1997	30.269
1998	26.359
1999	7.966
2000	1.810
2001	4.198
2002	22.742
2003	8.256
2004	7.264
2005	5.545
2006	15.845
2007	8.721
2008	14.893
2009	13.447
2010	15.352
2011	18.895
2012	44.436
2013	41.903
2014	25.668
2015	12.582
2016	30.474
2017	25.151
2018	72.935
2019	57.011
2020	269.334
2021	318.208
2022	87.319
2023	146.627
2024	114.560
2025	43.022
2026	19.464
2027	11.776
2028	8.040
2029	7.364