1978

7.2

1994

7.2

1986

7.7

1996

7.0

2015

6.5

1999

7.6

2005

4.3

2015

5.8

1984

5.9

1951

7.9

2007

7.9

2001

8.3

2020

6.7

1987

5.0

2015

6.1

1974

6.2

2003

8.7

1999

7.5

1990

6.8

1994

8.4