Year	Percent
1990	1.14325
1991	1.26465
1992	1.1814
1993	2.12943
1994	3.20892
1995	2.52403
1996	3.72996
1997	3.67074
1998	3.92409
1999	4.36103
2000	4.51512
2005	3.05964
2006	2.94804
2007	2.55077
2008	2.26578
2009	2.30302
2010	2.26967
2011	2.49238
2012	2.63771
2013	3.02217
2014	3.17771
2015	3.22846
2016	3.21708
2017	3.0565
2018	2.8524
2019	2.25048