2002

6.4

1992

5.0

2004

3.8

1998

5.8

1977

4.1

2017

6.7

1989

6.0

2008

6.8

2011

5.3

1991

5.8

2009

6.0

2015

4.6

1962

7.3

1953

7.9

1968

7.8

1972

6.4

1999

5.7

1996

7.6

1991

7.6