Year	Percent
1990	78.101
1991	79.196
1992	76.632
1993	77.373
1994	77.283
1995	76.958
1996	76.195
1997	68.117
1998	65.146
1999	64.828
2000	63.29
2001	63.106
2002	61.66
2003	62.276
2004	58.837
2005	61.357
2006	58.65
2007	59.1
2008	57.28
2009	55.44
2010	53.585
2011	51.72
2012	55.758
2013	59.721
2014	63.561
2015	67.235
2016	67.695
2017	67.099
2018	66.503
2019	65.908
2020	65.312
2021	64.717
2022	64.121
2023	63.525
2024	62.93
2025	62.334
2026	61.739
2027	61.143
2028	60.548
2029	59.952
2030	59.356