1975

4.5

1989

5.8

1989

6.1

1999

7.4

1988

5.5

2015

6.4

1993

6.7

1982

5.9

1976

4.9

2011

7.3

5.0

2012

7.3

2010

5.1

2013

6.5

2021

9.2

1990

6.3

1988

5.4

2021

6.2

2010

7.1