Year	Percent
1991	12.119
1992	12.615
1993	12.094
1994	9.342
1995	10.895
1996	11.168
1997	11.562
1998	11.585
1999	11.923
2000	12.187
2001	12.423
2002	13.1
2003	13.438
2004	14.02
2005	14.875
2006	15.671
2007	16.693
2008	17.766
2009	18.514
2010	19.662
2011	20.578
2012	21.613
2013	24.685
2014	28.611
2015	29.528
2016	29.906
2017	30.343
2018	30.991
2019	31.823
2020	32.581
2021	33.363
2022	34.148