Year	Percent
1990	53.299
1991	53.63
1992	53.397
1993	53.307
1994	54.41
1995	55.113
1996	56.416
1997	56.308
1998	56.216
1999	56.519
2000	56.689
2001	57.647
2002	58.359
2003	58.622
2004	59.081
2005	60.097
2006	60.647
2007	61.092
2008	61.362
2009	61.245
2010	60.966
2011	61.442
2012	61.573
2013	62.01
2014	62.9
2015	62.84
2016	63.921
2017	63.859
2018	63.79
2019	63.7
2020	63.58
2021	63.453
2022	63.302
2023	63.133
2024	62.958
2025	62.783
2026	62.642
2027	62.506
2028	62.372
2029	62.241
2030	62.112