Year	%
1990	29.44787223893443
1991	29.50538473383758
1992	29.55876230442647
1993	29.88421882385295
1994	29.620563750870378
1995	29.937027866186025
1996	30.037746504038882
1997	29.70986237728586
1998	29.93845313527021
1999	29.34027284244927
2000	29.931523767611598
2001	30.887633782251076
2002	30.7831498541083
2003	31.097427456137183
2004	30.90435126794899
2005	30.862800683461753
2006	30.430446796772056
2007	30.200689258668405
2008	30.167203269669486
2009	29.936085869598205
2010	29.775868172296015
2011	29.42691172414755
2012	29.038117404714242
2013	28.681918458747354
2014	28.494468349213978
2015	28.147988585135227
2016	28.066723667257786
2017	27.741656214242344
2018	27.62452640683553
2019	27.498677871462387
2020	27.325354680203056
2021	27.195025654949397