Year	Percent change
1980	63.475
1981	34.046
1982	18.991
1983	49.198
1984	55.305
1985	72.222
1986	76.38
1987	63.567
1988	62.192
1989	80.447
1990	112.526
1991	101.972
1992	68.456
1993	54.081
1994	44.736
1995	42.248
1996	28.342
1997	19.819
1998	10.809
1999	5.661
2000	4.761
2001	4.366
2002	13.967
2003	19.379
2004	9.159
2005	4.7
2006	6.398
2007	8.115
2008	7.877
2009	7.062
2010	6.699
2011	8.093
2012	8.098
2013	8.575
2014	8.877
2015	8.666
2016	9.639
2017	6.218
2018	7.607
2019	7.633
2020	7.216
2021	7.159
2022	6.96
2023	6.962
2024	6.983