Year | Value | 2021 | 1.5509852652351 | 2020 | 1.5552454673567 | 2019 | 1.5708061574724 | 2018 | 1.5745014382999 | 2017 | 1.5681234475394 | 2016 | 1.5223508099681 | 2015 | 1.4622998987472 | 2014 | 1.4429744237629 | 2013 | 1.3877370626128 | 2012 | 1.4160541207692 | 2011 | 1.3933711300897 | 2010 | 1.4618756448876 | 2009 | 1.4877404502211 | 2008 | 1.4635496904828 | 2007 | 1.3813072034064 | 2006 | 1.3420958814445 | 2005 | 1.3127907444698 | 2004 | 1.2765638051392 | 2003 | 1.2511572570425 | 2002 | 1.2534321163642 | 2001 | 1.2755308397097 | 2000 | 1.3177928549123 | 1999 | 1.3079300185881 | 1998 | 1.3384335431235 | 1997 | 1.3815268396945 | 1996 | 1.4292571862716 | 1995 | 1.4685433517913 | 1994 | 1.5897574523534 | 1993 | 1.6704186026007 | 1992 | 1.7505136259562 | 1991 | 1.8549672974148 | 1990 | 1.9308779307405 | 1989 | 2.0179885684532 | 1988 | 2.077879018416 | 1987 | 2.0970450219688 | 1986 | 2.1374991460428 | 1985 | 2.1615660300858 | 1984 | 2.1634257842037 | 1983 | 2.1427455828462 | 1982 | 2.1398813987054 | 1981 | 2.1499868287615 | 1980 | 2.1959092947303 | 1979 | 2.2549293850253 | 1978 | 2.2489833614821 | 1977 | 2.2842966747593 | 1976 | 2.3230815568357 | 1975 | 2.3388826453065 | 1974 | 2.3648864733824 | 1973 | 2.2493879841299 | 1972 | 2.2361570457615 | 1971 | 2.260558566946 | 1970 | 2.2875669890611 | 1969 | 2.3567932483045 | 1968 | 2.4581784579399 | 1967 | 2.4783210242227 | 1966 | 2.1273242948459 | 1965 | 2.2054530511597 | 1964 | 2.2596589474267 | 1963 | 2.3122549043833 | 1962 | 2.3069248046652 | 1961 | 2.3973610361082 | 1960 | 2.491058719839 |
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