Year	Percent
1990	9.36144
1991	7.5078
1992	6.99263
1993	6.14331
1994	7.12258
1995	7.4259
1996	7.53622
1997	8.76262
1998	6.7949
1999	6.68648
2000	1.66253
2001	1.80899
2002	1.99744
2003	2.0389
2004	1.94715
2005	1.99732
2006	1.94416
2007	2.70427
2008	2.41565
2009	3.38774
2010	2.54213
2011	2.27241
2012	2.60115
2013	2.52372