Year	Percent
1990	61.051
1991	61.441
1992	61.594
1993	61.035
1994	57.913
1995	57.952
1996	58.222
1997	58.702
1998	59.421
1999	60
2000	60.05
2001	59.805
2002	60.285
2003	59.612
2004	60.375
2005	60.499
2006	61.157
2007	60.839
2008	61.055
2009	60.61
2010	59.799
2011	59.631
2012	59.108
2013	58.586
2014	58.011
2015	57.71
2016	59.312
2017	59.181
2018	59.076
2019	58.966
2020	58.833
2021	58.699
2022	58.551
2023	58.387
2024	58.209
2025	58.016
2026	57.846
2027	57.669
2028	57.485
2029	57.295
2030	57.101