Year	Percent
1991	3.609
1992	3.687
1993	3.648
1994	3.753
1995	3.826
1996	3.865
1997	4.22
1998	4.206
1999	4.741
2000	4.622
2001	4.634
2002	4.7
2003	5.48
2004	5.936
2005	6.058
2006	6.589
2007	7.996
2008	8.867
2009	10.546
2010	12.22
2011	14.636
2012	17.221
2013	20.635
2014	30.888
2015	31.19
2016	31.343
2017	31.595
2018	31.782
2019	31.972
2020	32.207
2021	32.433
2022	32.651