Year	Percent
1990	36.47
1991	38.04
1992	38.17
1993	37.72
1994	37.62
1995	37.32
1996	36.68
1997	36.7
1998	35.93
1999	35.46
2000	34.1
2001	32.91
2002	31.11
2003	29.94
2004	29.16
2005	29.43
2006	29.23
2007	29.75
2008	29.72
2009	29.36
2010	28.76
2011	28.4
2012	28.71
2013	29.41
2014	30.17
2015	31.1
2016	31.66
2017	31.446
2018	31.233
2019	31.019
2020	30.806
2021	30.592
2022	30.379
2023	30.165
2024	29.951
2025	29.738
2026	29.524
2027	29.311
2028	29.097
2029	28.884
2030	28.67