Year	Percent
1991	43.383
1992	42.624
1993	42.264
1994	43.131
1995	43.512
1996	43.239
1997	43.714
1998	43.583
1999	43.634
2000	44.702
2001	44.148
2002	44.634
2003	44.822
2004	44.807
2005	45.181
2006	45.685
2007	47.569
2008	47.956
2009	48.415
2010	48.704
2011	48.218
2012	48.468
2013	48.606
2014	48.559
2015	47.917
2016	48.628
2017	48.251
2018	48.534
2019	48.923
2020	49.262
2021	49.576
2022	49.911