1999

7.6

2002

7.4

1984

7.2

1990

6.2

2005

5.6

2014

5.3

1991

6.7

1995

5.0

1993

7.7

1985

6.4

2005

7.0

1998

5.9

2006

7.7

1934

7.8

2007

6.0

1986

6.1

1977

7.0

1971

7.2

1989

6.9

1997

5.0