Year	Percent
1990	43.587
1991	44.006
1992	45.244
1993	45.385
1994	46.167
1995	46.818
1996	46.665
1997	46.121
1998	45.992
1999	45.569
2000	43.092
2001	41.506
2002	40.695
2003	41.243
2004	41.573
2005	41.982
2006	42.604
2007	43.276
2008	43.915
2009	42.923
2010	43.554
2011	44.927
2012	45.254
2013	45.373
2014	45.302
2015	45.526
2016	45.685
2017	45.84
2018	45.995
2019	46.15
2020	46.305
2021	46.46
2022	46.614
2023	46.769
2024	46.924
2025	47.079
2026	47.234
2027	47.389
2028	47.544
2029	47.699
2030	47.854