Year	Percent
1991	5.44551
1992	5.38731
1993	5.31177
1994	5.22211
1995	5.12108
1996	5.00603
1997	4.88381
1998	4.75703
1999	4.62245
2000	4.45394
2001	4.36099
2002	4.26295
2003	4.19925
2004	4.0883
2005	3.98179
2006	3.83985
2007	3.69279
2008	3.60784
2009	3.55753
2010	3.45962
2011	3.36575
2012	3.26638
2013	3.16312
2014	3.05603
2015	2.95642
2016	2.86416
2017	2.77441
2018	2.69505
2019	2.61614