Year	Percent
1991	3.911
1992	3.751
1993	3.743
1994	3.62
1995	3.598
1996	3.503
1997	3.582
1998	3.465
1999	3.485
2000	3.433
2001	3.446
2002	3.033
2003	2.623
2004	2.681
2005	2.454
2006	2.366
2007	2.285
2008	2.22
2009	2.217
2010	2.283
2011	1.889
2012	1.915
2013	1.666
2014	1.83
2015	1.855
2016	1.688
2017	1.635
2018	1.595
2019	1.55
2020	1.508
2021	1.457
2022	1.411