1968  -999.0  -999.0     8.6     8.1     7.1     6.5     7.5     6.8     8.0     7.8     7.3     7.2
1969     8.2     7.2     6.6     6.6     5.5     6.0     5.5     6.9     7.0     7.0     8.4     8.2
1970     8.2     9.0     7.0     8.2     7.1     7.2     8.0     7.8     9.1     9.0     8.9     6.7
1971     7.8     7.1     8.6     7.8     6.7     8.0     7.0     7.4     7.8     8.8     8.8     8.4
1972     8.5     9.3     8.8     7.1     8.0     7.2     7.4     7.1     8.4     8.6     8.6     8.1
1973     7.1     7.3     8.3     9.0     7.1     7.0     7.8     7.2     7.3     8.1     8.6     8.0
1974     7.2     8.3     7.8     5.6     7.4     7.5     7.2     6.6     7.8     8.6     7.2     8.3
1975     6.6     7.1     6.5     7.4     8.0     6.2     5.0     4.7     8.5     7.4     6.2     6.4
1976     6.0     7.7     6.0     8.7     8.0     7.6     8.2     7.1     7.1     8.1     7.8     7.7
1977     7.9     7.9     8.1     9.0     8.2     7.7     6.9     8.4     7.9     7.7     9.4     8.5
1978     7.9     8.0     8.5     8.6     8.8     7.5     5.0     7.8     9.0     8.2     8.0     8.5
1979     8.1     8.2     8.0     7.8     8.4     7.9     7.6     7.1     7.9     7.6     7.6     8.8
1980     8.4     8.9     8.4     8.2     9.1     7.5     7.9     7.7     8.0     7.9     8.2     8.8
1981     8.5     8.5     8.1     8.2     7.0     6.9     7.4     6.2     6.8     7.3     7.2     7.3
1982     7.3     6.8     8.5     7.8     8.3     7.7     7.2     6.4     7.0     6.7     7.6     8.0
1983     9.0     6.7     8.9     8.1     8.3     6.9     8.0     7.9     8.1     8.8     8.9     8.5
1984     8.0     8.4     8.5     7.6     6.7     7.0     7.0     7.4     6.6     7.2     7.1     7.4
1985     8.3     7.5     7.6     7.5     7.4     8.1     7.7     7.2     7.4     6.7     8.2     7.2
1986     8.3     7.5     8.5     9.3     9.1     9.4     8.4     9.1     9.1     8.9     9.4     8.0
1987     8.5     7.8     7.6     8.7     7.6     7.6     5.8     8.1     8.1     7.8     8.2     8.1
1988     7.4     8.1     7.9     8.4     7.4     8.4     7.9     6.8     8.0     8.0     7.8     7.8
1989     6.6     6.6     7.2     8.0     6.8     7.7     7.6     7.7     7.5     8.1     7.1     7.9
1990     9.0     7.6     9.1     8.3     7.7     7.1     7.1     7.4     7.2     7.9     8.3     7.7
1991     8.6     7.7     7.8     8.8     7.2     6.9     5.8     7.5     7.2     8.0     7.7     7.0
1992     9.2     7.8     9.1     8.7     7.2     7.2     7.0     8.2     7.9     8.7     8.0     7.9
1993     8.2     8.1     7.8     8.2     8.0     8.6     7.5     8.1     8.2     8.0     8.3     7.9
1994     8.1     8.3     7.8     8.7     6.6     8.5     8.1     8.4     8.3     8.9     8.3     8.5
1995     9.0     9.1     7.5     9.0     8.2     7.6     7.7     6.9     8.5     7.3     7.5     7.4
1996     7.4     6.9     7.1     7.4     8.0     7.7     7.7     7.2     8.2     7.7     7.8     7.6
1997     7.9     7.9     7.4     7.7     6.5     5.9     7.1     7.5     6.9     7.8     8.3     6.9
1998     7.9     6.2     7.3     6.7     6.1     7.2     6.7     7.2     7.7     8.1     7.7     7.8
1999     8.2     7.5     7.5     8.0     8.0     7.2     8.3     7.3     8.0     7.3     8.5     7.5
2000     6.5     7.3     7.1     8.0     7.0     8.1     7.3     8.1     8.1     8.2     6.3     7.3
2001     7.4     8.0     8.3     8.8     8.0     9.2     8.4     8.8     7.6     8.0     8.2     7.7
2002     8.2     8.0     8.2     8.4     8.1     7.2     7.2     8.0     7.5     7.7     8.3     8.2
2003     7.7     8.0     7.6     7.6     7.8     7.0     7.3     8.5     8.7     8.0     8.0     7.8
2004     7.0     8.8     8.4     8.7     8.2     9.2     8.7     8.4     8.5     7.2     8.1     7.5
2005     8.0     7.6     8.0     7.3     8.3     7.5     7.7     8.3     8.2     7.7     6.8     7.3
2006     7.1     7.6     7.6     7.5     7.7     7.4     8.0     6.3     8.2     8.1     8.5     7.5
2007     6.6     8.1     7.4     8.3     7.1     5.8     4.9     6.8     8.0     8.6     8.6     8.1
2008     8.6     8.3     8.2     8.1     7.9     7.1     7.8     8.5     7.8     7.8     7.7     8.0
2009     8.5     8.9     8.4     7.3     7.2     6.4     6.1     6.7     8.0     7.8     7.5     8.2
2010     8.0  -999.0     5.6     6.8     6.3     7.0     7.5     7.9     8.0     7.1     7.2     5.3
2011     5.2     6.8     7.5     7.8     7.6     6.9     6.2     7.0     8.2     8.2     8.0     8.8
2012     8.0     7.3     8.1     8.2     8.4     8.7     7.7     7.9     7.8     7.6     8.2     7.6
2013     8.1     7.8     7.9     8.5     8.5     8.3     8.8     8.3     8.6     9.3     8.0     8.2
2014     8.9     9.0     8.6     8.5     6.3     7.6     8.2     7.6     7.9     8.8     8.9     8.4
2015     8.7     8.6     8.4     7.0     7.9     7.7     6.9     7.2     7.8     7.7     8.3     7.8
2016     7.1     6.5     7.6     7.6     5.8     7.8     7.1     6.8     8.1     7.1     6.0     5.9
2017     6.6     7.2     7.8     7.6     8.2     8.4     7.9     8.0     7.5     8.8     7.8     7.5
2018     8.2     8.4     8.6     8.0     7.6     7.8     8.0     8.7     8.0     8.2     8.2     8.5
2019     8.5     7.7     8.2     8.5     7.6     8.1     6.8     6.8     7.2     7.4     7.4     7.8
2020     8.3     6.7     6.6     5.8     6.6     5.9     8.0     8.1     8.8     8.9     8.8     8.5
2021     8.9     8.7     8.9     8.7     7.4     7.8     7.0     7.6     8.2     8.0     7.8     8.4
2022     8.1     8.2     8.0     8.5     7.6     7.6     7.9     7.7     8.6     7.4     8.2     6.9
2023     7.6     8.0     6.9     7.2     8.0     6.9     6.3     8.5     8.2     8.0     7.5     6.8