Year	Percent
1991	42.32
1992	38.672
1993	40.549
1994	41.971
1995	37.816
1996	38.765
1997	40.113
1998	40.675
1999	42.502
2000	39.768
2001	39.297
2002	40.511
2003	46.25
2004	48.315
2005	48.35
2006	55.54
2007	57.555
2008	58.116
2009	61.922
2010	63.225
2011	63.605
2012	64.038
2013	62.308
2014	61.047
2015	58.52
2016	57.701
2017	58.203
2018	59.025
2019	59.891
2020	60.77
2021	61.653
2022	62.48