1992

6.8

2010

7.8

1972

7.9

1995

7.2

1996

7.7

1958

7.5

1999

7.8

1986

8.5

2009

8.3

1985

7.9

1999

8.4

1989

8.3

1999

8.2

2013

8.2

1997

8.0

2004

6.6

1990

8.1

1997

6.9

1981

7.4

1990

6.9