Year	Percent
1991	76.486
1992	78.655
1993	79.441
1994	80.711
1995	81.932
1996	82.79
1997	84.341
1998	84.611
1999	85.055
2000	86.004
2001	85.481
2002	86.026
2003	85.353
2004	84.991
2005	85.362
2006	84.277
2007	84.565
2008	84.39
2009	84.127
2010	83.101
2011	84.721
2012	85.579
2013	85.476
2014	85.705
2015	85.806
2016	86.833
2017	87.053
2018	87.297
2019	87.532
2020	87.776
2021	88.013
2022	88.234