1
2
3
4
5
6
7
8
9
10
11
12
1950
0
1.5
1951
1952
1953
2.2
2.4
1954
1955
2.7
2.9
1956
3.1
1957
1958
3.2
1959
3.3
1960
2.5
1961
3.5
3.7
1962
1963
3.8
4.0
1964
4.1
4.2
1965
4.5
4.6
4.7
4.4
3.4
1966
1.6
0.9
-0.9
-1.3
-1.7
-1.9
-2.1
-2.2
-2.3
1967
-2.9
-3.1
-3.6
-3.8
-4.1
-4.9
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
-4.7
1986
1987
1988
1989
-4.0
1990
-1.8
-1.1
-0.8
1991
-0.5
-0.4
-0.3
1992
-0.2
-0.1
1993
0.1
1994
0.2
0.4
1995
0.5
0.6
1996
0.7
0.8
1997
1.1
1.2
1998
1.3
1999
2000
1.7
1.8
2.1
2001
2.3
2002
2.6
2003
2004
2.8
2005
3.9
3.6
2006
2007
2008
2009
2010
2011
4.3
2012
2013
4.8
5.0
2014
2015
5.2
2016
5.1
2017
2018