Year	Percent change
1980	28.697
1981	21.352
1982	7.191
1983	3.421
1984	2.274
1985	2.46
1986	2.75
1987	3.048
1988	7.146
1989	5.701
1990	8.574
1991	9.333
1992	6.213
1993	4.801
1994	6.266
1995	4.481
1996	4.925
1997	4.439
1998	7.513
1999	0.813
2000	2.259
2001	4.066
2002	2.763
2003	3.515
2004	3.591
2005	2.754
2006	2.242
2007	2.535
2008	4.674
2009	2.757
2010	2.939
2011	4.026
2012	2.187
2013	1.301
2014	1.275
2015	0.706
2016	0.972
2017	1.944
2018	1.477
2019	1.351
2020	1.55
2021	1.7
2022	1.8
2023	1.9
2024	2