Year	Percent
1991	2.874
1992	2.817
1993	2.629
1994	2.696
1995	2.567
1996	2.368
1997	2.432
1998	2.553
1999	2.472
2000	2.465
2001	2.542
2002	2.589
2003	2.543
2004	2.59
2005	2.565
2006	2.624
2007	2.79
2008	2.763
2009	2.767
2010	2.861
2011	2.844
2012	2.9
2013	2.982
2014	3.018
2015	2.805
2016	2.855
2017	2.746
2018	2.709
2019	2.731
2020	2.765
2021	2.804
2022	2.852