1999

7.4

1995

8.2

2003

7.2

2009

6.1

2002

6.6

1992

6.4

2009

6.2

1994

2.8

1931

0.0

1992

7.0

1973

7.1

2003

6.6

1995

6.8

1985

6.7

1986

6.2

1990

6.3

1991

7.0

2010

6.4

2005

6.2

1973

7.5