Year	Percent
1991	37.719
1992	39.182
1993	39.264
1994	40.14
1995	40.081
1996	41.712
1997	41.766
1998	41.06
1999	42.912
2000	43.887
2001	44.496
2002	44.777
2003	45.428
2004	46.368
2005	46.678
2006	47.134
2007	47.408
2008	47.408
2009	47.342
2010	47.952
2011	48.791
2012	49.171
2013	49.515
2014	51.646
2015	52.939
2016	53.111
2017	52.73
2018	53.77
2019	54.776
2020	55.71
2021	56.589
2022	57.326