1971    -999    -999     6.6     7.1     5.0     5.8     7.1     6.1     5.4     6.8     6.1     7.9
1972     9.4     7.6     6.8     9.2     5.4     5.0     6.3     5.7     6.7     6.8     6.9     8.8
1973     9.4     7.4     6.8     6.8     6.0     6.0     7.0     7.2     6.5     4.6     7.6     7.4
1974     7.6     8.3     7.0     6.8     6.5     7.6     5.5     5.8     7.3     4.1     6.4     6.0
1975     6.9     7.9     6.3     7.3     5.2     6.8     5.6     6.2     6.6     5.8     7.4     8.5
1976     7.9     7.8     8.1     9.2     8.4     7.5     7.2     8.0     6.8     6.4     6.6     8.0
1977     7.1     8.4     6.5     7.5     4.4     7.4     4.4     6.1     7.8     6.9     7.6     7.6
1978     6.5     7.3     8.0     7.6     4.1     4.2     6.6     7.1     6.1     6.2     7.8     7.2
1979     8.3     7.7     6.4     7.2     5.9     5.1     5.1     4.6     6.5     7.0     6.8     7.7
1980     6.3     7.5     7.2     7.8     8.1     6.4     3.8     6.1     7.1     4.8     7.7     7.2
1981     6.9     6.7     5.8     6.0     5.6     3.5     3.6     2.3     4.5     6.7     5.6     6.6
1982     6.4     8.2     6.0     4.8     4.4     3.8     4.5     5.1     6.3     4.9     6.5     6.4
1983     8.2     7.6     7.3     5.9     7.0     5.8     6.9     5.8     7.1     6.2     5.9     7.7
1984     7.8     6.1     6.5     5.7     5.0     3.8     2.2     7.1     7.1     6.5     5.9     6.5
1985     6.4     8.5     6.6     7.8     7.0     4.8     5.6     4.0     5.0     4.6     6.9     5.3
1986     7.2     5.2     7.6     5.7     4.7     5.6     5.4     5.1     5.9     5.6     5.7     4.0
1987     6.2     7.8     6.8     7.6     4.4     4.0     4.8     5.2     4.8     5.1     6.2     6.0
1988     6.3     7.2     7.2     6.8     5.7     5.3     5.7     5.2     5.3     5.3     6.6     7.4
1989     6.5     6.5     6.8     5.8     5.7     5.5     5.1     4.6     5.3     5.2     5.7     6.9
1990     6.2     7.0     6.3     6.7     7.4     4.6     6.6     6.0     6.1     6.5     5.9     6.3
1991     7.8     7.1    -999    -999    -999    -999    -999    -999    -999    -999    -999    -999