Year	Percent
1990	45.68
1991	46.286
1992	46.802
1993	47.333
1994	48.006
1995	48.553
1996	49.027
1997	49.482
1998	52.556
1999	52.707
2000	52.86
2001	53.017
2002	53.173
2003	54.865
2004	55.06
2005	55.29
2006	56.124
2007	55.038
2008	53.928
2009	52.795
2010	49.884
2011	49.056
2012	50.297
2013	49.453
2014	48.517
2015	52.203
2016	55.808
2017	55.424
2018	55.034
2019	54.633
2020	54.221
2021	53.806
2022	53.381
2023	52.947
2024	52.507
2025	52.062
2026	51.624
2027	51.184
2028	50.74
2029	50.293
2030	49.843