Year	Percent
1990	73.136
1991	72.512
1992	71.946
1993	71.606
1994	71.107
1995	70.699
1996	70.347
1997	70.05
1998	69.872
1999	69.73
2000	69.195
2001	68.654
2002	68.108
2003	67.557
2004	67.002
2005	66.441
2006	65.876
2007	65.306
2008	64.732
2009	64.154
2010	63.571
2011	62.985
2012	62.394
2013	61.8
2014	61.301
2015	61.039
2016	60.825
2017	60.596
2018	60.367
2019	60.139
2020	59.91
2021	59.681
2022	59.452
2023	59.223
2024	58.994
2025	58.766
2026	58.537
2027	58.308
2028	58.079
2029	57.85
2030	57.621