Year	Percent change
1980	24.668
1981	24.353
1982	21.42
1983	19.859
1984	18.419
1985	19.531
1986	23.113
1987	16.361
1988	13.48
1989	13.706
1990	20.347
1991	19.498
1992	15.869
1993	14.352
1994	10.881
1995	8.818
1996	7.873
1997	5.441
1998	4.517
1999	2.141
2000	2.897
2001	3.642
2002	3.921
2003	3.45
2004	3.02
2005	3.486
2006	3.314
2007	2.989
2008	4.23
2009	1.347
2010	4.704
2011	3.118
2012	1.035
2013	-0.854
2014	-1.394
2015	-1.094
2016	0.013
2017	1.138
2018	0.774
2019	1.055
2020	1.443
2021	1.653
2022	1.732
2023	1.761
2024	1.777