Year	Percent
1991	28.916
1992	29.662
1993	32.074
1994	34.306
1995	34.99
1996	34.62
1997	36.845
1998	38.521
1999	40.888
2000	42.282
2001	41.653
2002	43.768
2003	45.349
2004	45.117
2005	45.774
2006	45.374
2007	46.163
2008	45.75
2009	44.949
2010	44.812
2011	44.762
2012	44.805
2013	46.886
2014	47.352
2015	47.432
2016	46.721
2017	46.417
2018	46.736
2019	47
2020	47.295
2021	47.449
2022	47.763