Year	Percent
1990	58.308
1991	58.472
1992	58.609
1993	58.714
1994	58.779
1995	58.802
1996	58.768
1997	58.692
1998	58.6
1999	58.534
2000	58.521
2001	58.75
2002	59.034
2003	59.365
2004	59.729
2005	60.113
2006	60.541
2007	61.035
2008	61.363
2009	61.874
2010	61.82
2011	62.496
2012	63.032
2013	63.666
2014	64.187
2015	64.573
2016	64.954
2017	65.321
2018	65.683
2019	66.035
2020	66.371
2021	66.71
2022	67.033
2023	67.347
2024	67.66
2025	67.975
2026	68.308
2027	68.644
2028	68.98
2029	69.31
2030	69.632