Year	Percent
1991	1.681
1992	1.524
1993	1.814
1994	1.843
1995	1.794
1996	1.921
1997	1.837
1998	1.986
1999	1.84
2000	1.714
2001	1.658
2002	1.807
2003	1.816
2004	1.786
2005	1.547
2006	1.524
2007	1.389
2008	1.295
2009	1.453
2010	1.232
2011	1.118
2012	1.205
2013	1.253
2014	1.298
2015	1.254
2016	1.269
2017	1.273
2018	1.288
2019	1.301
2020	1.314
2021	1.327
2022	1.341