Year	Percent
1992	1.23854
1993	1.35718
1994	2.9983
1995	4.13555
1996	3.98378
1997	4.18545
1998	3.74927
1999	3.76195
2000	2.93541
2001	2.99499
2002	3.18697
2003	3.1933
2004	3.43253
2005	3.4287
2006	3.28057
2007	2.92056
2008	2.92076
2009	3.80873
2010	3.80376
2011	3.81668
2012	3.39269
2013	3.40698
2014	3.42423
2015	3.44262
2016	3.46139
2017	3.48261
2018	3.49772
2019	3.47221
2020	3.39206