Year	Percent
1991	34.067
1992	36.206
1993	37.19
1994	36.736
1995	39.008
1996	40.705
1997	42.89
1998	44.711
1999	48.157
2000	50.416
2001	48.172
2002	47.202
2003	46.5
2004	46.956
2005	47.852
2006	48.833
2007	51.177
2008	51.845
2009	50.269
2010	47.97
2011	45.355
2012	50.195
2013	44.956
2014	47.751
2015	47.435
2016	47.22
2017	46.812
2018	46.776
2019	47.089
2020	47.462
2021	47.855
2022	48.137