Year	Percent
1991	42.573
1992	43.36
1993	44.052
1994	44.693
1995	42.726
1996	42.5
1997	42.251
1998	42.167
1999	42.415
2000	42.76
2001	43.256
2002	43.155
2003	42.966
2004	43.131
2005	43.324
2006	43.628
2007	44.395
2008	45.925
2009	45.676
2010	46.622
2011	47.398
2012	46.179
2013	45.664
2014	43.418
2015	45.565
2016	43.743
2017	43.779
2018	43.914
2019	43.9
2020	43.895
2021	43.92
2022	43.924