Year	Percent
1991	54.779
1992	56.893
1993	61.264
1994	63.656
1995	65.703
1996	67.45
1997	67.779
1998	69.766
1999	70.759
2000	72.932
2001	71.698
2002	73.215
2003	73.602
2004	71.64
2005	72.584
2006	75.179
2007	75.136
2008	75.496
2009	78.019
2010	79.234
2011	78.474
2012	79.827
2013	80.598
2014	80.24
2015	80.024
2016	80.729
2017	80.521
2018	80.829
2019	81.405
2020	82
2021	82.711
2022	83.124
