Year	Percent
1991	44.993
1992	45.938
1993	45.633
1994	45.554
1995	45.432
1996	45.66
1997	45.265
1998	45.484
1999	45.653
2000	45.302
2001	48.199
2002	48.71
2003	49.107
2004	50.249
2005	50.329
2006	49.639
2007	51.043
2008	51.513
2009	53.235
2010	51.314
2011	51.375
2012	51.638
2013	51
2014	52.442
2015	52.248
2016	53.819
2017	54.209
2018	54.646
2019	55.116
2020	55.542
2021	55.996
2022	56.354