Year	%
1990	17.7619645597879
1991	17.900291626163
1992	18.0368778594205
1993	18.1680022105554
1994	18.2754359467252
1995	18.3787465940054
1996	18.320020613244
1997	18.2422802850356
1998	18.1887783003391
1999	18.1588775613203
2000	18.1078807142189
2001	18.0807642205819
2002	18.0509502628387
2003	18.0293184222457
2004	18.0171254688274
2005	18.0033277870216
2006	18.0184708173651
2007	18.0384455156817
2008	18.0676547120715
2009	18.0813201035375
2010	18.091799896854
2011	18.1016982720206
2012	18.1175684064753
2013	18.1414496507702
2014	18.1679114550526
2015	18.2009931010239
2016	18.235496939919
2017	18.3007920037271
2018	18.3696515956334
2019	18.4353600332019
2020	18.4993585233622
2021	18.5692983182835
2022	18.6255806237558