Year	Percent
1981	10.87077
1982	0.85408
1983	8.59072
1984	1.748
1985	1.20975
1986	8.08127
1987	24.19969
1988	1.5702
1989	4.80201
1990	9.42712
1991	-0.40862
1992	5.73423
1993	3.62558
1994	6.29544
1995	7.41226
1996	4.66968
1997	3.48619
1998	3.29605
1999	5.00365
2000	3.97296
2001	5.23368
2002	7.66036
2003	4.72246
2004	3.10991
2005	4.45412
2006	4.37152
2007	15.39722
2008	2.67702
2009	4.64069
2010	9.70658
2011	6.01592
2012	3.33342
2013	0.54098
2014	4.18103
2015	5.11665
2016	6.58574
2017	5.51663