1975

7.3

1989

6.5

2002

5.7

2000

7.6

1993

7.1

1994

7.8

1951

8.6

1984

7.1

1986

7.0

1985

6.0

1982

6.7

1996

5.3

1997

3.4

2002

7.1

2008

6.3