1999

6.4

1997

7.9

2010

8.2

1988

6.2

2014

7.7

2008

6.8

1998

7.8

2019

8.1

1965

7.4

2015

7.6

2002

7.1

2023

8.0

1982

6.8

2000

8.1

1999

6.6

2022

7.7

1985

7.7

2011

7.3

1975

7.7

2013

6.5