Year	Percent
1990	89.607
1991	89.612
1992	89.558
1993	88.716
1994	87.83
1995	86.899
1996	85.899
1997	84.846
1998	83.74
1999	82.584
2000	81.38
2001	80.135
2002	78.85
2003	78.198
2004	77.521
2005	76.825
2006	76.105
2007	75.368
2008	74.622
2009	73.876
2010	73.139
2011	74.027
2012	73.93
2013	73.782
2014	73.631
2015	73.524
2016	73.442
2017	73.442
2018	73.448
2019	73.455
2020	73.461
2021	73.467
2022	73.474
2023	73.482
2024	73.492
2025	73.506
2026	73.524
2027	73.546
2028	73.573
2029	73.609
2030	73.657