1995

5.9

2002

5.6

2005

6.3

1998

6.6

1985

6.2

1990

6.5

1996

6.5

1997

5.2

2002

4.3

2003

5.6

1989

6.8

1997

6.1

2005

6.1

2005

6.9

2006

4.4

1999

8.2

2003

7.1

2003

6.7

1994

6.2

1984

7.7