Year	Percent
1991	2.708
1992	2.834
1993	2.774
1994	2.874
1995	2.972
1996	2.913
1997	3.247
1998	3.143
1999	3.469
2000	3.21
2001	3.138
2002	3.104
2003	3.811
2004	4.138
2005	3.908
2006	4.071
2007	5.53
2008	6.384
2009	8.597
2010	10.344
2011	13.098
2012	16.835
2013	21.176
2014	32.791
2015	33.099
2016	32.639
2017	32.437
2018	32.163
2019	31.881
2020	31.725
2021	31.565
2022	31.407