2015

6.6

1985

7.1

1990

6.8

2001

7.3

2003

7.1

2002

6.2

2004

6.3

1985

7.7

2006

6.6

1968

6.1

2007

5.5

2016

6.2

1992

6.6

2000

5.9

1978

6.3

2000

6.0

2000

5.2

2007

5.5

1973

3.7

2005

5.6