Year	Percent
1990	84.075
1991	84.093
1992	84.059
1993	84.144
1994	83.673
1995	83.292
1996	82.729
1997	82.092
1998	81.761
1999	81.358
2000	81.029
2001	80.978
2002	80.918
2003	80.765
2004	80.694
2005	80.682
2006	80.79
2007	80.735
2008	80.638
2009	80.488
2010	80.276
2011	79.994
2012	79.986
2013	79.944
2014	79.801
2015	79.592
2016	79.345
2017	79.347
2018	79.338
2019	79.322
2020	79.301
2021	79.271
2022	79.238
2023	79.206
2024	79.179
2025	79.16
2026	79.144
2027	79.135
2028	79.135
2029	79.142
2030	79.157