Year	Percent
1990	32.72
1991	32.823
1992	32.927
1993	33.031
1994	33.135
1995	33.239
1996	33.343
1997	33.448
1998	33.552
1999	33.657
2000	33.762
2001	33.117
2002	32.478
2003	31.846
2004	31.221
2005	30.602
2006	29.99
2007	29.385
2008	28.787
2009	28.197
2010	27.614
2011	27.6
2012	27.595
2013	27.596
2014	27.598
2015	27.599
2016	27.6
2017	27.336
2018	27.071
2019	26.807
2020	26.543
2021	26.279
2022	26.014
2023	25.75
2024	25.486
2025	25.221
2026	24.957
2027	24.693
2028	24.429
2029	24.164
2030	23.9