Annual
1977-12-31 8.1375
1978-12-31 8.9927
1979-12-31 10.6224
1980-12-31 11.582
1981-12-31 11.2768
1982-12-31 10.6044
1983-12-31 11.0089
1984-12-31 10.4463
1985-12-31 10.1097
1986-12-31 11.4492
1987-12-31 12.7826
1988-12-31 13.8911
1989-12-31 12.7786
1990-12-31 13.9129
1991-12-31 13.7428
1992-12-31 13.6721
1993-12-31 11.6148
1994-12-31 11.8451
1995-12-31 12.2092
1996-12-31 12.0791
1997-12-31 12.6818
1998-12-31 12.8387
1999-12-31 12.5541
2000-12-31 11.8057
2001-12-31 11.2335
2002-12-31 11.7265
2003-12-31 12.7337
2004-12-31 14.2707
2005-12-31 14.1477
2006-12-31 14.3182
2007-12-31 15.6201
2008-12-31 14.4304
2009-12-31 12.1432
2010-12-31 12.0099
2011-12-31 12.4792
2012-12-31 12.2956
2013-12-31 12.1343
2014-12-31 12.7771
2015-12-31 11.8505
2016-12-31 10.5121
2017-12-31 10.0443
2018-12-31 10.4629
2019-12-31 10.0024
2020-12-31 9.9568
2021-12-31 10.6924
2022-12-31 9.6791
2023-12-31 9.7342