Year	Percent
1990	48.239
1991	48.907
1992	48.468
1993	48.378
1994	48.876
1995	48.627
1996	48.736
1997	48.403
1998	48.236
1999	47.983
2000	47.052
2001	46.784
2002	46.482
2003	46.182
2004	45.9
2005	45.567
2006	45.315
2007	45.209
2008	45.143
2009	44.97
2010	44.785
2011	44.626
2012	44.433
2013	44.198
2014	44.059
2015	43.98
2016	43.846
2017	43.674
2018	43.503
2019	43.332
2020	43.16
2021	42.989
2022	42.817
2023	42.646
2024	42.475
2025	42.303
2026	42.132
2027	41.96
2028	41.789
2029	41.618
2030	41.446