1996

5.8

2008

6.6

2002

4.2

2015

5.7

2001

5.9

1997

5.9

2003

7.4

2002

6.6

1992

3.8

2002

6.3

2001

6.8

2002

5.9

1987

4.5

2015

6.4

1956

5.1

1993

6.7

2017

6.2

1999

7.1

2001

7.8

2013

5.5