Year	Percent
1990	45.847
1991	47.959
1992	50.079
1993	50.251
1994	50.429
1995	50.611
1996	50.796
1997	50.986
1998	51.862
1999	52.741
2000	52.604
2001	52.492
2002	52.37
2003	52.227
2004	52.059
2005	51.874
2006	52.255
2007	52.655
2008	53.065
2009	53.052
2010	53.783
2011	53.454
2012	53.119
2013	52.77
2014	52.613
2015	50.877
2016	52.873
2017	52.878
2018	52.874
2019	52.873
2020	52.882
2021	52.901
2022	52.931
2023	52.964
2024	52.989
2025	52.998
2026	52.995
2027	52.979
2028	52.957
2029	52.943
2030	52.945