Year	%
1990	17.3913043478261
1991	20
1992	20.8333333333333
1993	20
1994	19.2307692307692
1995	20
1996	20
1997	20
1998	20
1999	19.6078431372549
2000	19.2982456140351
2001	20.6349206349206
2002	20
2003	19.2307692307692
2004	19.5402298850575
2005	19
2006	18.4210526315789
2007	17.96875
2008	16.9014084507042
2009	16.5605095541401
2010	16.2790697674419
2011	16.4021164021164
2012	15.9420289855072
2013	15.7205240174673
2014	15.4150197628458
2015	15.4676258992806
2016	15.359477124183
2017	15.1785714285714
2018	14.9051490514905
2019	14.8514851485149
2020	14.7392290249433
2021	14.5833333333333
2022	14.4212523719165