1987

5.7

2016

6.7

1992

4.7

1998

6.3

1968

7.3

1999

6.2

1997

4.8

1998

4.8

1973

7.1

2008

5.1

1993

6.2

2008

6.1

2000

6.3

2015

7.0

1986

6.4

1989

6.2

2003

5.8

1978

6.6

2005

6.2

1966

5.0