Year	Percent
1991	1.858
1992	1.818
1993	1.867
1994	1.893
1995	2.055
1996	2.211
1997	2.49
1998	2.532
1999	2.757
2000	2.941
2001	3.238
2002	3.564
2003	3.92
2004	4.453
2005	5.171
2006	5.284
2007	5.391
2008	5.385
2009	5.5
2010	5.605
2011	6.277
2012	6.568
2013	6.885
2014	7.588
2015	8.476
2016	9.062
2017	9.581
2018	9.957
2019	10.28
2020	10.543
2021	10.836
2022	11.014