2005

6.5

1981

6.8

2011

6.6

2017

6.3

1958

6.7

1966

6.6

1978

7.2

1961

5.6

1950

6.6

1963

5.9

2019

5.3

1992

7.4

1964

4.1

2016

6.2

2001

6.7

1986

7.4

1999

6.1

2006

6.6

1962

7.0

1995

6.7