Year	Percent
1990	35.99
1991	36.235
1992	36.199
1993	35.62
1994	35.78
1995	35.856
1996	36.797
1997	37.715
1998	38.612
1999	39.482
2000	39.797
2001	40.24
2002	40.689
2003	41.26
2004	42.034
2005	42.525
2006	43.036
2007	43.624
2008	44.15
2009	44.594
2010	45.151
2011	45.67
2012	46.035
2013	46.37
2014	46.634
2015	46.757
2016	46.126
2017	46.397
2018	46.662
2019	46.907
2020	47.123
2021	47.343
2022	47.53
2023	47.707
2024	47.903
2025	48.139
2026	48.444
2027	48.787
2028	49.149
2029	49.494
2030	49.802