1988

4.7

1991

5.3

1992

7.6

1989

5.2

1981

6.5

1991

0.0

2003

6.3

1985

4.1

1989

7.2

1985

5.6

1990

8.0

2006

5.0

1997

7.0

2002

4.8

2013

5.9