Year	Percent
1991	62.033
1992	62.99
1993	63.623
1994	63.539
1995	63.528
1996	63.76
1997	63.57
1998	63.387
1999	63.623
2000	63.505
2001	64.082
2002	63.92
2003	64.158
2004	64.104
2005	64.212
2006	64.984
2007	65.624
2008	65.62
2009	66.639
2010	66.783
2011	67.116
2012	67.022
2013	67.167
2014	67.507
2015	67.916
2016	67.987
2017	67.896
2018	68.063
2019	68.288
2020	68.345
2021	68.518
2022	68.617