Year	Percent
1973-01-01	6.894030000000000
1974-01-01	17.374800000000000
1975-01-01	20.698200000000000
1976-01-01	20.212500000000000
1977-01-01	21.356900000000000
1978-01-01	21.792900000000000
1979-01-01	16.142400000000000
1980-01-01	11.709700000000000
1981-01-01	11.660100000000000
1982-01-01	12.887700000000000
1983-01-01	14.862800000000000
1984-01-01	16.541200000000000
1985-01-01	18.442600000000000
1986-01-01	23.365600000000000
1987-01-01	22.749800000000000
1988-01-01	24.568000000000000
1989-01-01	23.076900000000000
1990-01-01	20.608300000000000
1991-01-01	23.631300000000000
1992-01-01	24.003800000000000
1993-01-01	25.895400000000000
1994-01-01	26.041800000000000
1995-01-01	26.198200000000000
1996-01-01	27.221999999999998
1997-01-01	33.454000000000000
1998-01-01	47.287500000000000
1999-01-01	49.066200000000000
2000-01-01	41.983300000000000
2001-01-01	44.106400000000000
2002-01-01	44.210100000000000
2003-01-01	41.824000000000000
2004-01-01	38.394000000000000
2005-01-01	32.573700000000000
2006-01-01	30.807600000000000
2007-01-01	33.935600000000000
2008-01-01	32.548900000000000
2009-01-01	48.801300000000000
2010-01-01	44.888800000000000
2011-01-01	44.933200000000000
2012-01-01	46.203800000000000
2013-01-01	49.287000000000000
2014-01-01	52.517700000000000
2015-01-01	72.124500000000000
2016-01-01	87.988999999999990