Year	Percent
1991	40.765
1992	41.617
1993	42.778
1994	43.666
1995	44.827
1996	44.805
1997	44.794
1998	45.831
1999	46.94
2000	47.743
2001	51.547
2002	54.167
2003	56.994
2004	60.503
2005	62.345
2006	64.522
2007	66.447
2008	67.197
2009	68.33
2010	71.017
2011	72.808
2012	73.749
2013	76.242
2014	76.79
2015	77.278
2016	77.178
2017	77.354
2018	78.116
2019	78.662
2020	79.214
2021	79.866
2022	80.286