Year	Percent
1989	2.48019
1990	2.49326
1991	2.34691
1992	2.48476
1993	1.96191
1994	1.72497
1995	1.71634
1996	1.68605
1997	1.6748
1998	1.7033
1999	1.92205
2000	1.89294
2001	2.08118
2002	2.18541
2003	2.11569
2004	2.06371
2005	2.00873
2006	2.01072
2007	1.91465
2008	1.87816
2009	2.06743
2010	1.89671
2011	1.82193
2012	1.83856
2013	1.87233
2014	1.91534
2015	1.93492
2016	1.93061
2017	1.90884