Year	Percent
1988	3.91169
1989	4.422
1990	4.42928
1991	4.76223
1992	5.25106
1993	5.39774
1994	6.28967
1995	7.29328
1996	7.4561
1997	9.16593
1998	12.28068
1999	15.16199
2000	9.66482
2001	9.35257
2002	9.38057
2003	9.55277
2004	9.57233
2005	10.19058
2006	10.32369
2007	9.08328
2008	8.46886
2009	8.93825
2010	9.00304
2011	9.30535
2012	9.78771
2013	10.25362
2014	9.11055
2015	9.61708
2016	10.1442