Year	Percent
1991	16.618
1992	17.574
1993	18.317
1994	19.284
1995	20.127
1996	20.803
1997	23.587
1998	25.265
1999	24.701
2000	23.599
2001	23.875
2002	25.153
2003	25.316
2004	26.278
2005	28.364
2006	30.315
2007	30.496
2008	30.79
2009	31.234
2010	32.006
2011	32.753
2012	33.449
2013	34.254
2014	34.375
2015	35.117
2016	35.741
2017	36.596
2018	37.866
2019	39.251
2020	40.58
2021	41.888
2022	43.048