Year	Ratio
1970-01-01	0.1693599969148640
1971-01-01	0.1647299975156780
1972-01-01	0.1684899926185610
1973-01-01	0.1762299984693530
1974-01-01	0.1749500036239620
1975-01-01	0.1833399981260300
1976-01-01	0.1893299967050550
1977-01-01	0.1985500007867810
1978-01-01	0.2049700021743770
1980-01-01	0.2303200066089630
1981-01-01	0.2373799979686740
1982-01-01	0.5036299824714660
1984-01-01	0.4755100011825560
1985-01-01	0.4864499866962430
1986-01-01	0.5446500182151790
1988-01-01	0.5036299824714660
1989-01-01	0.5303500294685360
1990-01-01	0.5495899915695190
1991-01-01	0.5479199886322020
1993-01-01	0.3517400026321410
1994-01-01	0.5033400058746340
1995-01-01	0.5123100280761720
1999-01-01	0.0846299976110458
2000-01-01	0.0000000000000000
2001-01-01	0.0000000000000000
2002-01-01	0.4565699994564060
2003-01-01	0.5627899765968320
2004-01-01	0.4343400001525880
2005-01-01	0.5871099829673770
2006-01-01	0.6293799877166750
2007-01-01	0.6206600069999690
2008-01-01	0.6438900232315060
2009-01-01	0.6647899746894840
2010-01-01	0.6860700249671940
2011-01-01	0.7177799940109250
2012-01-01	0.7242400050163270
2013-01-01	0.7059400081634520
2014-01-01	0.7009599804878230
2015-01-01	0.6911500096321110
2017-01-01	0.6800500154495240