Year	Percent
1980	36.20089
1981	6.20348
1982	2.89731
1983	4.46306
1984	5.8383
1985	7.86026
1986	8.96224
1987	8.94653
1988	9.55013
1989	12.81584
1990	9.13547
1991	8.18375
1992	7.23794
1993	5.78878
1994	5.39912
1995	6.92904
1996	4.57873
1997	3.99929
1998	5.92972
1999	6.16017
2000	4.21656
2001	7.40155
2002	7.75452
2003	5.89753
2004	6.18579
2005	8.05109
2006	20.6447
2007	12.83143
2008	10.1831
2009	7.20176
2010	5.69796
2011	3.63397
2012	4.82233
2013	5.70476