Year	Percent
1990	52.718
1991	52.294
1992	52.052
1993	51.995
1994	52.535
1995	53.09
1996	53.644
1997	54.195
1998	54.728
1999	55.232
2000	55.703
2001	56.217
2002	56.713
2003	57.198
2004	57.68
2005	58.167
2006	58.676
2007	59.189
2008	59.701
2009	60.206
2010	60.699
2011	61.196
2012	61.678
2013	61.886
2014	62.101
2015	62.454
2016	62.683
2017	62.965
2018	63.246
2019	63.514
2020	63.765
2021	64.016
2022	64.253
2023	64.48
2024	64.704
2025	64.929
2026	65.167
2027	65.406
2028	65.645
2029	65.883
2030	66.12