Year	Percent
1991	3.654
1992	3.468
1993	3.089
1994	2.87
1995	2.886
1996	2.71
1997	2.546
1998	1.986
1999	1.915
2000	1.898
2001	1.791
2002	1.727
2003	1.587
2004	1.502
2005	1.486
2006	1.408
2007	1.45
2008	1.37
2009	1.405
2010	1.473
2011	1.474
2012	1.469
2013	1.467
2014	1.442
2015	1.394
2016	1.362
2017	1.35
2018	1.296
2019	1.259
2020	1.221
2021	1.182
2022	1.143