Year	Percent
1990	79.588
1991	79.502
1992	79.195
1993	79.263
1994	79.352
1995	79.363
1996	79.362
1997	79.353
1998	79.476
1999	79.507
2000	79.532
2001	79.313
2002	79.545
2003	79.618
2004	79.853
2005	79.27
2006	78.671
2007	78.057
2008	77.428
2009	76.785
2010	76.131
2011	75.464
2012	74.787
2013	74.103
2014	73.408
2015	73.448
2016	73.774
2017	73.561
2018	73.347
2019	73.128
2020	72.905
2021	72.674
2022	72.44
2023	72.204
2024	71.97
2025	71.738
2026	71.503
2027	71.271
2028	71.042
2029	70.814
2030	70.587