1931

8.1

1968

7.2

2013

7.4

2001

6.1

1990

6.9

1960

7.2

1997

7.0

1990

8.5

1986

5.8

1999

6.8

1997

6.8

2005

5.5

1989

7.2

1990

7.5

2018

4.6

1995

8.0

1993

6.5

2008

8.5

1972

8.7

1974

8.6