Year	Ratio
1971-01-01	0.0855600014328957
1972-01-01	0.0818300023674965
1974-01-01	0.0981199964880943
1979-01-01	0.1416399925947190
1980-01-01	0.1920499950647350
1982-01-01	0.1484600007534030
1983-01-01	0.1385899931192400
1984-01-01	0.1204600036144260
1986-01-01	0.2152799963951110
1987-01-01	0.1967599987983700
1988-01-01	0.2054399996995930
1989-01-01	0.2178400009870530
1990-01-01	0.2186100035905840
1991-01-01	0.2157299965620040
1994-01-01	0.2836599946022030
1995-01-01	0.2585900127887730
1996-01-01	0.2424400001764300
1997-01-01	0.2581999897956850
1998-01-01	0.2385299950838090
1999-01-01	0.2299499958753590
2000-01-01	0.2757700085639950
2001-01-01	0.2707200050354000
2002-01-01	0.3567900061607360
2003-01-01	0.3348200023174290
2004-01-01	0.3348200023174290
2005-01-01	0.3209699988365170
2008-01-01	0.3120200037956240
2009-01-01	0.4424600005149840
2010-01-01	0.4304299950599670
2011-01-01	0.4371899962425230
2012-01-01	0.4649899899959560
2014-01-01	0.4815500080585480