Year	Percent
1988	4.0687
1989	4.20062
1990	3.94348
1991	4.69286
1992	4.04695
1993	4.24878
1994	4.78352
1995	5.80488
1996	6.87211
1997	6.53827
1998	5.61952
1999	5.74213
2000	6.25555
2001	6.97023
2002	6.2378
2003	5.94772
2004	5.99807
2005	5.8038
2006	6.0724
2007	6.40329
2008	6.77773
2009	9.09372
2010	7.18055
2011	6.8708
2012	6.63226
2013	8.07394
2014	8.58626
2015	7.51776
2016	7.12969