1997

7.2

2002

6.4

1990

7.0

1975

6.7

1987

7.3

1989

7.0

1992

6.7

1998

6.6

2014

5.9

2002

5.5

2016

5.7

1984

7.2

1987

6.5

1982

6.7

1994

5.9

1986

6.1

1992

5.3

1994

6.7

1996

5.7

1988

7.0