Year	Percent
1991	25.353
1992	25.662
1993	25.745
1994	25.097
1995	24.196
1996	24.253
1997	24.618
1998	24.728
1999	24.801
2000	24.652
2001	24.588
2002	23.988
2003	24.43
2004	24.029
2005	27.079
2006	30.48
2007	33.876
2008	37.342
2009	41.037
2010	44.272
2011	47.96
2012	47.92
2013	47.794
2014	47.711
2015	47.559
2016	46.638
2017	45.864
2018	45.216
2019	44.632
2020	44.113
2021	43.659
2022	43.256