Year	Percent
1990	33.411
1991	33.597
1992	33.52
1993	32.934
1994	33.038
1995	33.057
1996	33.893
1997	34.724
1998	35.545
1999	36.352
2000	36.656
2001	37.008
2002	37.359
2003	37.818
2004	38.47
2005	38.862
2006	39.281
2007	39.778
2008	40.22
2009	40.585
2010	41.05
2011	41.476
2012	41.759
2013	42.01
2014	42.191
2015	42.237
2016	41.585
2017	41.752
2018	41.908
2019	42.043
2020	42.149
2021	42.25
2022	42.326
2023	42.381
2024	42.423
2025	42.462
2026	42.521
2027	42.581
2028	42.64
2029	42.695
2030	42.744